Move bisect-perf-regression.py into auto_bisect directory.

tools/bisect-perf-regression.py

-#!/usr/bin/env python
-# Copyright (c) 2013 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-"""Performance Test Bisect Tool
-
-This script bisects a series of changelists using binary search. It starts at
-a bad revision where a performance metric has regressed, and asks for a last
-known-good revision. It will then binary search across this revision range by
-syncing, building, and running a performance test. If the change is
-suspected to occur as a result of WebKit/V8 changes, the script will
-further bisect changes to those depots and attempt to narrow down the revision
-range.
-
-Example usage using SVN revisions:
-
-./tools/bisect-perf-regression.py -c\
-  "out/Release/performance_ui_tests --gtest_filter=ShutdownTest.SimpleUserQuit"\
-  -g 168222 -b 168232 -m shutdown/simple-user-quit
-
-Be aware that if you're using the git workflow and specify an SVN revision,
-the script will attempt to find the git SHA1 where SVN changes up to that
-revision were merged in.
-
-Example usage using git hashes:
-
-./tools/bisect-perf-regression.py -c\
-  "out/Release/performance_ui_tests --gtest_filter=ShutdownTest.SimpleUserQuit"\
-  -g 1f6e67861535121c5c819c16a666f2436c207e7b\
-  -b b732f23b4f81c382db0b23b9035f3dadc7d925bb\
-  -m shutdown/simple-user-quit
-"""
-
-import copy
-import datetime
-import errno
-import hashlib
-import math
-import optparse
-import os
-import re
-import shlex
-import shutil
-import StringIO
-import sys
-import time
-import zipfile
-
-sys.path.append(os.path.join(os.path.dirname(__file__), 'telemetry'))
-
-from auto_bisect import bisect_utils
-from auto_bisect import builder
-from auto_bisect import math_utils
-from auto_bisect import request_build
-from auto_bisect import source_control as source_control_module
-from auto_bisect import ttest
-from telemetry.util import cloud_storage
-
-# Below is the map of "depot" names to information about each depot. Each depot
-# is a repository, and in the process of bisecting, revision ranges in these
-# repositories may also be bisected.
-#
-# Each depot information dictionary may contain:
-#   src: Path to the working directory.
-#   recurse: True if this repository will get bisected.
-#   depends: A list of other repositories that are actually part of the same
-#       repository in svn. If the repository has any dependent repositories
-#       (e.g. skia/src needs skia/include and skia/gyp to be updated), then
-#       they are specified here.
-#   svn: URL of SVN repository. Needed for git workflow to resolve hashes to
-#       SVN revisions.
-#   from: Parent depot that must be bisected before this is bisected.
-#   deps_var: Key name in vars variable in DEPS file that has revision
-#       information.
-DEPOT_DEPS_NAME = {
-    'chromium': {
-        'src': 'src',
-        'recurse': True,
-        'depends': None,
-        'from': ['cros', 'android-chrome'],
-        'viewvc':
-            'http://src.chromium.org/viewvc/chrome?view=revision&revision=',
-        'deps_var': 'chromium_rev'
-    },
-    'webkit': {
-        'src': 'src/third_party/WebKit',
-        'recurse': True,
-        'depends': None,
-        'from': ['chromium'],
-        'viewvc':
-            'http://src.chromium.org/viewvc/blink?view=revision&revision=',
-        'deps_var': 'webkit_revision'
-    },
-    'angle': {
-        'src': 'src/third_party/angle',
-        'src_old': 'src/third_party/angle_dx11',
-        'recurse': True,
-        'depends': None,
-        'from': ['chromium'],
-        'platform': 'nt',
-        'deps_var': 'angle_revision'
-    },
-    'v8': {
-        'src': 'src/v8',
-        'recurse': True,
-        'depends': None,
-        'from': ['chromium'],
-        'custom_deps': bisect_utils.GCLIENT_CUSTOM_DEPS_V8,
-        'viewvc': 'https://code.google.com/p/v8/source/detail?r=',
-        'deps_var': 'v8_revision'
-    },
-    'v8_bleeding_edge': {
-        'src': 'src/v8_bleeding_edge',
-        'recurse': True,
-        'depends': None,
-        'svn': 'https://v8.googlecode.com/svn/branches/bleeding_edge',
-        'from': ['v8'],
-        'viewvc': 'https://code.google.com/p/v8/source/detail?r=',
-        'deps_var': 'v8_revision'
-    },
-    'skia/src': {
-        'src': 'src/third_party/skia/src',
-        'recurse': True,
-        'svn': 'http://skia.googlecode.com/svn/trunk/src',
-        'depends': ['skia/include', 'skia/gyp'],
-        'from': ['chromium'],
-        'viewvc': 'https://code.google.com/p/skia/source/detail?r=',
-        'deps_var': 'skia_revision'
-    },
-    'skia/include': {
-        'src': 'src/third_party/skia/include',
-        'recurse': False,
-        'svn': 'http://skia.googlecode.com/svn/trunk/include',
-        'depends': None,
-        'from': ['chromium'],
-        'viewvc': 'https://code.google.com/p/skia/source/detail?r=',
-        'deps_var': 'None'
-    },
-    'skia/gyp': {
-        'src': 'src/third_party/skia/gyp',
-        'recurse': False,
-        'svn': 'http://skia.googlecode.com/svn/trunk/gyp',
-        'depends': None,
-        'from': ['chromium'],
-        'viewvc': 'https://code.google.com/p/skia/source/detail?r=',
-        'deps_var': 'None'
-    }
-}
-
-DEPOT_NAMES = DEPOT_DEPS_NAME.keys()
-
-CROS_CHROMEOS_PATTERN = 'chromeos-base/chromeos-chrome'
-
-# Possible return values from BisectPerformanceMetrics.RunTest.
-BUILD_RESULT_SUCCEED = 0
-BUILD_RESULT_FAIL = 1
-BUILD_RESULT_SKIPPED = 2
-
-# Maximum time in seconds to wait after posting build request to the try server.
-# TODO: Change these values based on the actual time taken by buildbots on
-# the try server.
-MAX_MAC_BUILD_TIME = 14400
-MAX_WIN_BUILD_TIME = 14400
-MAX_LINUX_BUILD_TIME = 14400
-
-# The confidence percentage at which confidence can be consider "high".
-HIGH_CONFIDENCE = 95
-
-# Patch template to add a new file, DEPS.sha under src folder.
-# This file contains SHA1 value of the DEPS changes made while bisecting
-# dependency repositories. This patch send along with DEPS patch to try server.
-# When a build requested is posted with a patch, bisect builders on try server,
-# once build is produced, it reads SHA value from this file and appends it
-# to build archive filename.
-DEPS_SHA_PATCH = """diff --git src/DEPS.sha src/DEPS.sha
-new file mode 100644
---- /dev/null
-+++ src/DEPS.sha
-@@ -0,0 +1 @@
-+%(deps_sha)s
-"""
-
-# The possible values of the --bisect_mode flag, which determines what to
-# use when classifying a revision as "good" or "bad".
-BISECT_MODE_MEAN = 'mean'
-BISECT_MODE_STD_DEV = 'std_dev'
-BISECT_MODE_RETURN_CODE = 'return_code'
-
-# The perf dashboard looks for a string like "Estimated Confidence: 95%"
-# to decide whether or not to cc the author(s). If you change this, please
-# update the perf dashboard as well.
-RESULTS_BANNER = """
-===== BISECT JOB RESULTS =====
-Status: %(status)s
-
-Test Command: %(command)s
-Test Metric: %(metrics)s
-Relative Change: %(change)s
-Estimated Confidence: %(confidence).02f%%"""
-
-# The perf dashboard specifically looks for the string
-# "Author  : " to parse out who to cc on a bug. If you change the
-# formatting here, please update the perf dashboard as well.
-RESULTS_REVISION_INFO = """
-===== SUSPECTED CL(s) =====
-Subject : %(subject)s
-Author  : %(author)s%(email_info)s%(commit_info)s
-Commit  : %(cl)s
-Date    : %(cl_date)s"""
-
-REPRO_STEPS_LOCAL = """
-==== INSTRUCTIONS TO REPRODUCE ====
-To run locally:
- - Use the test command given under 'BISECT JOB RESULTS' above.
- - Consider using a profiler. Pass --profiler=list to list available profilers.
-"""
-
-REPRO_STEPS_TRYJOB = """
-To reproduce on a performance try bot:
- 1. Edit run-perf-test.cfg
- 2. Upload your patch with: $ git cl upload --bypass-hooks
- 3. Send to the try server: $ git cl try -m tryserver.chromium.perf -b <bot>
-
-Notes:
- a) Follow the in-file instructions in run-perf-test.cfg.
- b) run-perf-test.cfg is under tools/ or under third_party/WebKit/Tools.
- c) Do your edits preferably under a new git branch.
- d) --browser=release and --browser=android-chromium-testshell are supported
-    depending on the platform (desktop|android).
- e) Strip any src/ directories from the head of relative path names.
- f) Make sure to use the appropriate bot on step 3.
-
-For more details please visit
-https://sites.google.com/a/chromium.org/dev/developers/performance-try-bots"""
-
-REPRO_STEPS_TRYJOB_TELEMETRY = """
-To reproduce on a performance try bot:
-%(command)s
-(Where <bot-name> comes from tools/perf/run_benchmark --browser=list)
-
-For more details please visit
-https://sites.google.com/a/chromium.org/dev/developers/performance-try-bots
-"""
-
-RESULTS_THANKYOU = """
-===== THANK YOU FOR CHOOSING BISECT AIRLINES =====
-Visit http://www.chromium.org/developers/core-principles for Chrome's policy
-on perf regressions.
-Contact chrome-perf-dashboard-team with any questions or suggestions about
-bisecting.
-.                   .-----.
-.     .---.         \      \==)
-.     |PERF\         \       \\
-.     |     ---------'-------'-----------.
-.     .     0 0 0 0 0 0 0 0 0 0 0 0 0 0 |_`-.
-.      \_____________.-------._______________)
-.                   /       /
-.                  /      /
-.                 /     /==)
-.                ._____."""
-
-
-def _AddAdditionalDepotInfo(depot_info):
-  """Adds additional depot info to the global depot variables."""
-  global DEPOT_DEPS_NAME
-  global DEPOT_NAMES
-  DEPOT_DEPS_NAME = dict(DEPOT_DEPS_NAME.items() + depot_info.items())
-  DEPOT_NAMES = DEPOT_DEPS_NAME.keys()
-
-
-def ConfidenceScore(good_results_lists, bad_results_lists):
-  """Calculates a confidence score.
-
-  This score is a percentage which represents our degree of confidence in the
-  proposition that the good results and bad results are distinct groups, and
-  their differences aren't due to chance alone.
-
-
-  Args:
-    good_results_lists: A list of lists of "good" result numbers.
-    bad_results_lists: A list of lists of "bad" result numbers.
-
-  Returns:
-    A number in the range [0, 100].
-  """
-  # If there's only one item in either list, this means only one revision was
-  # classified good or bad; this isn't good enough evidence to make a decision.
-  # If an empty list was passed, that also implies zero confidence.
-  if len(good_results_lists) <= 1 or len(bad_results_lists) <= 1:
-    return 0.0
-
-  # Flatten the lists of results lists.
-  sample1 = sum(good_results_lists, [])
-  sample2 = sum(bad_results_lists, [])
-
-  # If there were only empty lists in either of the lists (this is unexpected
-  # and normally shouldn't happen), then we also want to return 0.
-  if not sample1 or not sample2:
-    return 0.0
-
-  # The p-value is approximately the probability of obtaining the given set
-  # of good and bad values just by chance.
-  _, _, p_value = ttest.WelchsTTest(sample1, sample2)
-  return 100.0 * (1.0 - p_value)
-
-
-def GetSHA1HexDigest(contents):
-  """Returns SHA1 hex digest of the given string."""
-  return hashlib.sha1(contents).hexdigest()
-
-
-def GetZipFileName(build_revision=None, target_arch='ia32', patch_sha=None):
-  """Gets the archive file name for the given revision."""
-  def PlatformName():
-    """Return a string to be used in paths for the platform."""
-    if bisect_utils.IsWindowsHost():
-      # Build archive for x64 is still stored with the "win32" suffix.
-      # See chromium_utils.PlatformName().
-      if bisect_utils.Is64BitWindows() and target_arch == 'x64':
-        return 'win32'
-      return 'win32'
-    if bisect_utils.IsLinuxHost():
-      # Android builds are also archived with the "full-build-linux prefix.
-      return 'linux'
-    if bisect_utils.IsMacHost():
-      return 'mac'
-    raise NotImplementedError('Unknown platform "%s".' % sys.platform)
-
-  base_name = 'full-build-%s' % PlatformName()
-  if not build_revision:
-    return base_name
-  if patch_sha:
-    build_revision = '%s_%s' % (build_revision , patch_sha)
-  return '%s_%s.zip' % (base_name, build_revision)
-
-
-def GetRemoteBuildPath(build_revision, target_platform='chromium',
-                       target_arch='ia32', patch_sha=None):
-  """Returns the URL to download the build from."""
-  def GetGSRootFolderName(target_platform):
-    """Returns the Google Cloud Storage root folder name."""
-    if bisect_utils.IsWindowsHost():
-      if bisect_utils.Is64BitWindows() and target_arch == 'x64':
-        return 'Win x64 Builder'
-      return 'Win Builder'
-    if bisect_utils.IsLinuxHost():
-      if target_platform == 'android':
-        return 'android_perf_rel'
-      return 'Linux Builder'
-    if bisect_utils.IsMacHost():
-      return 'Mac Builder'
-    raise NotImplementedError('Unsupported Platform "%s".' % sys.platform)
-
-  base_filename = GetZipFileName(
-      build_revision, target_arch, patch_sha)
-  builder_folder = GetGSRootFolderName(target_platform)
-  return '%s/%s' % (builder_folder, base_filename)
-
-
-def FetchFromCloudStorage(bucket_name, source_path, destination_path):
-  """Fetches file(s) from the Google Cloud Storage.
-
-  Args:
-    bucket_name: Google Storage bucket name.
-    source_path: Source file path.
-    destination_path: Destination file path.
-
-  Returns:
-    Downloaded file path if exists, otherwise None.
-  """
-  target_file = os.path.join(destination_path, os.path.basename(source_path))
-  try:
-    if cloud_storage.Exists(bucket_name, source_path):
-      print 'Fetching file from gs//%s/%s ...' % (bucket_name, source_path)
-      cloud_storage.Get(bucket_name, source_path, destination_path)
-      if os.path.exists(target_file):
-        return target_file
-    else:
-      print ('File gs://%s/%s not found in cloud storage.' % (
-          bucket_name, source_path))
-  except Exception as e:
-    print 'Something went wrong while fetching file from cloud: %s' % e
-    if os.path.exists(target_file):
-      os.remove(target_file)
-  return None
-
-
-# This is copied from build/scripts/common/chromium_utils.py.
-def MaybeMakeDirectory(*path):
-  """Creates an entire path, if it doesn't already exist."""
-  file_path = os.path.join(*path)
-  try:
-    os.makedirs(file_path)
-  except OSError as e:
-    if e.errno != errno.EEXIST:
-      return False
-  return True
-
-
-# This was copied from build/scripts/common/chromium_utils.py.
-def ExtractZip(filename, output_dir, verbose=True):
-  """ Extract the zip archive in the output directory."""
-  MaybeMakeDirectory(output_dir)
-
-  # On Linux and Mac, we use the unzip command as it will
-  # handle links and file bits (executable), which is much
-  # easier then trying to do that with ZipInfo options.
-  #
-  # The Mac Version of unzip unfortunately does not support Zip64, whereas
-  # the python module does, so we have to fall back to the python zip module
-  # on Mac if the file size is greater than 4GB.
-  #
-  # On Windows, try to use 7z if it is installed, otherwise fall back to python
-  # zip module and pray we don't have files larger than 512MB to unzip.
-  unzip_cmd = None
-  if ((bisect_utils.IsMacHost()
-       and os.path.getsize(filename) < 4 * 1024 * 1024 * 1024)
-      or bisect_utils.IsLinuxHost()):
-    unzip_cmd = ['unzip', '-o']
-  elif (bisect_utils.IsWindowsHost()
-        and os.path.exists('C:\\Program Files\\7-Zip\\7z.exe')):
-    unzip_cmd = ['C:\\Program Files\\7-Zip\\7z.exe', 'x', '-y']
-
-  if unzip_cmd:
-    # Make sure path is absolute before changing directories.
-    filepath = os.path.abspath(filename)
-    saved_dir = os.getcwd()
-    os.chdir(output_dir)
-    command = unzip_cmd + [filepath]
-    result = bisect_utils.RunProcess(command)
-    os.chdir(saved_dir)
-    if result:
-      raise IOError('unzip failed: %s => %s' % (str(command), result))
-  else:
-    assert bisect_utils.IsWindowsHost() or bisect_utils.IsMacHost()
-    zf = zipfile.ZipFile(filename)
-    for name in zf.namelist():
-      if verbose:
-        print 'Extracting %s' % name
-      zf.extract(name, output_dir)
-      if bisect_utils.IsMacHost():
-        # Restore permission bits.
-        os.chmod(os.path.join(output_dir, name),
-                 zf.getinfo(name).external_attr >> 16L)
-
-
-def WriteStringToFile(text, file_name):
-  """Writes text to a file, raising an RuntimeError on failure."""
-  try:
-    with open(file_name, 'wb') as f:
-      f.write(text)
-  except IOError:
-    raise RuntimeError('Error writing to file [%s]' % file_name )
-
-
-def ReadStringFromFile(file_name):
-  """Writes text to a file, raising an RuntimeError on failure."""
-  try:
-    with open(file_name) as f:
-      return f.read()
-  except IOError:
-    raise RuntimeError('Error reading file [%s]' % file_name )
-
-
-def ChangeBackslashToSlashInPatch(diff_text):
-  """Formats file paths in the given patch text to Unix-style paths."""
-  if not diff_text:
-    return None
-  diff_lines = diff_text.split('\n')
-  for i in range(len(diff_lines)):
-    line = diff_lines[i]
-    if line.startswith('--- ') or line.startswith('+++ '):
-      diff_lines[i] = line.replace('\\', '/')
-  return '\n'.join(diff_lines)
-
-
-def _ParseRevisionsFromDEPSFileManually(deps_file_contents):
-  """Parses the vars section of the DEPS file using regular expressions.
-
-  Args:
-    deps_file_contents: The DEPS file contents as a string.
-
-  Returns:
-    A dictionary in the format {depot: revision} if successful, otherwise None.
-  """
-  # We'll parse the "vars" section of the DEPS file.
-  rxp = re.compile('vars = {(?P<vars_body>[^}]+)', re.MULTILINE)
-  re_results = rxp.search(deps_file_contents)
-
-  if not re_results:
-    return None
-
-  # We should be left with a series of entries in the vars component of
-  # the DEPS file with the following format:
-  # 'depot_name': 'revision',
-  vars_body = re_results.group('vars_body')
-  rxp = re.compile("'(?P<depot_body>[\w_-]+)':[\s]+'(?P<rev_body>[\w@]+)'",
-                   re.MULTILINE)
-  re_results = rxp.findall(vars_body)
-
-  return dict(re_results)
-
-
-def _WaitUntilBuildIsReady(
-    fetch_build, bot_name, builder_host, builder_port, build_request_id,
-    max_timeout):
-  """Waits until build is produced by bisect builder on try server.
-
-  Args:
-    fetch_build: Function to check and download build from cloud storage.
-    bot_name: Builder bot name on try server.
-    builder_host Try server host name.
-    builder_port: Try server port.
-    build_request_id: A unique ID of the build request posted to try server.
-    max_timeout: Maximum time to wait for the build.
-
-  Returns:
-     Downloaded archive file path if exists, otherwise None.
-  """
-  # Build number on the try server.
-  build_num = None
-  # Interval to check build on cloud storage.
-  poll_interval = 60
-  # Interval to check build status on try server in seconds.
-  status_check_interval = 600
-  last_status_check = time.time()
-  start_time = time.time()
-  while True:
-    # Checks for build on gs://chrome-perf and download if exists.
-    res = fetch_build()
-    if res:
-      return (res, 'Build successfully found')
-    elapsed_status_check = time.time() - last_status_check
-    # To avoid overloading try server with status check requests, we check
-    # build status for every 10 minutes.
-    if elapsed_status_check > status_check_interval:
-      last_status_check = time.time()
-      if not build_num:
-        # Get the build number on try server for the current build.
-        build_num = request_build.GetBuildNumFromBuilder(
-            build_request_id, bot_name, builder_host, builder_port)
-      # Check the status of build using the build number.
-      # Note: Build is treated as PENDING if build number is not found
-      # on the the try server.
-      build_status, status_link = request_build.GetBuildStatus(
-          build_num, bot_name, builder_host, builder_port)
-      if build_status == request_build.FAILED:
-        return (None, 'Failed to produce build, log: %s' % status_link)
-    elapsed_time = time.time() - start_time
-    if elapsed_time > max_timeout:
-      return (None, 'Timed out: %ss without build' % max_timeout)
-
-    print 'Time elapsed: %ss without build.' % elapsed_time
-    time.sleep(poll_interval)
-    # For some reason, mac bisect bots were not flushing stdout periodically.
-    # As a result buildbot command is timed-out. Flush stdout on all platforms
-    # while waiting for build.
-    sys.stdout.flush()
-
-
-def _UpdateV8Branch(deps_content):
-  """Updates V8 branch in DEPS file to process v8_bleeding_edge.
-
-  Check for "v8_branch" in DEPS file if exists update its value
-  with v8_bleeding_edge branch. Note: "v8_branch" is added to DEPS
-  variable from DEPS revision 254916, therefore check for "src/v8":
-  <v8 source path> in DEPS in order to support prior DEPS revisions
-  and update it.
-
-  Args:
-    deps_content: DEPS file contents to be modified.
-
-  Returns:
-    Modified DEPS file contents as a string.
-  """
-  new_branch = r'branches/bleeding_edge'
-  v8_branch_pattern = re.compile(r'(?<="v8_branch": ")(.*)(?=")')
-  if re.search(v8_branch_pattern, deps_content):
-    deps_content = re.sub(v8_branch_pattern, new_branch, deps_content)
-  else:
-    # Replaces the branch assigned to "src/v8" key in DEPS file.
-    # Format of "src/v8" in DEPS:
-    # "src/v8":
-    #    (Var("googlecode_url") % "v8") + "/trunk@" + Var("v8_revision"),
-    # So, "/trunk@" is replace with "/branches/bleeding_edge@"
-    v8_src_pattern = re.compile(
-        r'(?<="v8"\) \+ "/)(.*)(?=@" \+ Var\("v8_revision"\))', re.MULTILINE)
-    if re.search(v8_src_pattern, deps_content):
-      deps_content = re.sub(v8_src_pattern, new_branch, deps_content)
-  return deps_content
-
-
-def _UpdateDEPSForAngle(revision, depot, deps_file):
-  """Updates DEPS file with new revision for Angle repository.
-
-  This is a hack for Angle depot case because, in DEPS file "vars" dictionary
-  variable contains "angle_revision" key that holds git hash instead of
-  SVN revision.
-
-  And sometimes "angle_revision" key is not specified in "vars" variable,
-  in such cases check "deps" dictionary variable that matches
-  angle.git@[a-fA-F0-9]{40}$ and replace git hash.
-  """
-  deps_var = DEPOT_DEPS_NAME[depot]['deps_var']
-  try:
-    deps_contents = ReadStringFromFile(deps_file)
-    # Check whether the depot and revision pattern in DEPS file vars variable
-    # e.g. "angle_revision": "fa63e947cb3eccf463648d21a05d5002c9b8adfa".
-    angle_rev_pattern = re.compile(r'(?<="%s": ")([a-fA-F0-9]{40})(?=")' %
-                                   deps_var, re.MULTILINE)
-    match = re.search(angle_rev_pattern % deps_var, deps_contents)
-    if match:
-      # Update the revision information for the given depot
-      new_data = re.sub(angle_rev_pattern, revision, deps_contents)
-    else:
-      # Check whether the depot and revision pattern in DEPS file deps
-      # variable. e.g.,
-      # "src/third_party/angle": Var("chromium_git") +
-      # "/angle/angle.git@fa63e947cb3eccf463648d21a05d5002c9b8adfa",.
-      angle_rev_pattern = re.compile(
-          r'(?<=angle\.git@)([a-fA-F0-9]{40})(?=")', re.MULTILINE)
-      match = re.search(angle_rev_pattern, deps_contents)
-      if not match:
-        print 'Could not find angle revision information in DEPS file.'
-        return False
-      new_data = re.sub(angle_rev_pattern, revision, deps_contents)
-    # Write changes to DEPS file
-    WriteStringToFile(new_data, deps_file)
-    return True
-  except IOError, e:
-    print 'Something went wrong while updating DEPS file, %s' % e
-  return False
-
-
-def _TryParseHistogramValuesFromOutput(metric, text):
-  """Attempts to parse a metric in the format HISTOGRAM <graph: <trace>.
-
-  Args:
-    metric: The metric as a list of [<trace>, <value>] strings.
-    text: The text to parse the metric values from.
-
-  Returns:
-    A list of floating point numbers found, [] if none were found.
-  """
-  metric_formatted = 'HISTOGRAM %s: %s= ' % (metric[0], metric[1])
-
-  text_lines = text.split('\n')
-  values_list = []
-
-  for current_line in text_lines:
-    if metric_formatted in current_line:
-      current_line = current_line[len(metric_formatted):]
-
-      try:
-        histogram_values = eval(current_line)
-
-        for b in histogram_values['buckets']:
-          average_for_bucket = float(b['high'] + b['low']) * 0.5
-          # Extends the list with N-elements with the average for that bucket.
-          values_list.extend([average_for_bucket] * b['count'])
-      except Exception:
-        pass
-
-  return values_list
-
-
-def _TryParseResultValuesFromOutput(metric, text):
-  """Attempts to parse a metric in the format RESULT <graph>: <trace>= ...
-
-  Args:
-    metric: The metric as a list of [<trace>, <value>] string pairs.
-    text: The text to parse the metric values from.
-
-  Returns:
-    A list of floating point numbers found.
-  """
-  # Format is: RESULT <graph>: <trace>= <value> <units>
-  metric_re = re.escape('RESULT %s: %s=' % (metric[0], metric[1]))
-
-  # The log will be parsed looking for format:
-  # <*>RESULT <graph_name>: <trace_name>= <value>
-  single_result_re = re.compile(
-      metric_re + '\s*(?P<VALUE>[-]?\d*(\.\d*)?)')
-
-  # The log will be parsed looking for format:
-  # <*>RESULT <graph_name>: <trace_name>= [<value>,value,value,...]
-  multi_results_re = re.compile(
-      metric_re + '\s*\[\s*(?P<VALUES>[-]?[\d\., ]+)\s*\]')
-
-  # The log will be parsed looking for format:
-  # <*>RESULT <graph_name>: <trace_name>= {<mean>, <std deviation>}
-  mean_stddev_re = re.compile(
-      metric_re +
-      '\s*\{\s*(?P<MEAN>[-]?\d*(\.\d*)?),\s*(?P<STDDEV>\d+(\.\d*)?)\s*\}')
-
-  text_lines = text.split('\n')
-  values_list = []
-  for current_line in text_lines:
-    # Parse the output from the performance test for the metric we're
-    # interested in.
-    single_result_match = single_result_re.search(current_line)
-    multi_results_match = multi_results_re.search(current_line)
-    mean_stddev_match = mean_stddev_re.search(current_line)
-    if (not single_result_match is None and
-        single_result_match.group('VALUE')):
-      values_list += [single_result_match.group('VALUE')]
-    elif (not multi_results_match is None and
-          multi_results_match.group('VALUES')):
-      metric_values = multi_results_match.group('VALUES')
-      values_list += metric_values.split(',')
-    elif (not mean_stddev_match is None and
-          mean_stddev_match.group('MEAN')):
-      values_list += [mean_stddev_match.group('MEAN')]
-
-  values_list = [float(v) for v in values_list
-                 if bisect_utils.IsStringFloat(v)]
-
-  # If the metric is times/t, we need to sum the timings in order to get
-  # similar regression results as the try-bots.
-  metrics_to_sum = [
-      ['times', 't'],
-      ['times', 'page_load_time'],
-      ['cold_times', 'page_load_time'],
-      ['warm_times', 'page_load_time'],
-  ]
-
-  if metric in metrics_to_sum:
-    if values_list:
-      values_list = [reduce(lambda x, y: float(x) + float(y), values_list)]
-
-  return values_list
-
-
-def _ParseMetricValuesFromOutput(metric, text):
-  """Parses output from performance_ui_tests and retrieves the results for
-  a given metric.
-
-  Args:
-    metric: The metric as a list of [<trace>, <value>] strings.
-    text: The text to parse the metric values from.
-
-  Returns:
-    A list of floating point numbers found.
-  """
-  metric_values = _TryParseResultValuesFromOutput(metric, text)
-
-  if not metric_values:
-    metric_values = _TryParseHistogramValuesFromOutput(metric, text)
-
-  return metric_values
-
-
-def _GenerateProfileIfNecessary(command_args):
-  """Checks the command line of the performance test for dependencies on
-  profile generation, and runs tools/perf/generate_profile as necessary.
-
-  Args:
-    command_args: Command line being passed to performance test, as a list.
-
-  Returns:
-    False if profile generation was necessary and failed, otherwise True.
-  """
-  if '--profile-dir' in ' '.join(command_args):
-    # If we were using python 2.7+, we could just use the argparse
-    # module's parse_known_args to grab --profile-dir. Since some of the
-    # bots still run 2.6, have to grab the arguments manually.
-    arg_dict = {}
-    args_to_parse = ['--profile-dir', '--browser']
-
-    for arg_to_parse in args_to_parse:
-      for i, current_arg in enumerate(command_args):
-        if arg_to_parse in current_arg:
-          current_arg_split = current_arg.split('=')
-
-          # Check 2 cases, --arg=<val> and --arg <val>
-          if len(current_arg_split) == 2:
-            arg_dict[arg_to_parse] = current_arg_split[1]
-          elif i + 1 < len(command_args):
-            arg_dict[arg_to_parse] = command_args[i+1]
-
-    path_to_generate = os.path.join('tools', 'perf', 'generate_profile')
-
-    if arg_dict.has_key('--profile-dir') and arg_dict.has_key('--browser'):
-      profile_path, profile_type = os.path.split(arg_dict['--profile-dir'])
-      return not bisect_utils.RunProcess(['python', path_to_generate,
-          '--profile-type-to-generate', profile_type,
-          '--browser', arg_dict['--browser'], '--output-dir', profile_path])
-    return False
-  return True
-
-
-def _AddRevisionsIntoRevisionData(revisions, depot, sort, revision_data):
-  """Adds new revisions to the revision_data dictionary and initializes them.
-
-  Args:
-    revisions: List of revisions to add.
-    depot: Depot that's currently in use (src, webkit, etc...)
-    sort: Sorting key for displaying revisions.
-    revision_data: A dictionary to add the new revisions into.
-        Existing revisions will have their sort keys adjusted.
-  """
-  num_depot_revisions = len(revisions)
-
-  for _, v in revision_data.iteritems():
-    if v['sort'] > sort:
-      v['sort'] += num_depot_revisions
-
-  for i in xrange(num_depot_revisions):
-    r = revisions[i]
-    revision_data[r] = {
-        'revision' : r,
-        'depot' : depot,
-        'value' : None,
-        'perf_time' : 0,
-        'build_time' : 0,
-        'passed' : '?',
-        'sort' : i + sort + 1,
-    }
-
-
-def _PrintThankYou():
-  print RESULTS_THANKYOU
-
-
-def _PrintTableRow(column_widths, row_data):
-  """Prints out a row in a formatted table that has columns aligned.
-
-  Args:
-    column_widths: A list of column width numbers.
-    row_data: A list of items for each column in this row.
-  """
-  assert len(column_widths) == len(row_data)
-  text = ''
-  for i in xrange(len(column_widths)):
-    current_row_data = row_data[i].center(column_widths[i], ' ')
-    text += ('%%%ds' % column_widths[i]) % current_row_data
-  print text
-
-
-def _PrintStepTime(revision_data_sorted):
-  """Prints information about how long various steps took.
-
-  Args:
-    revision_data_sorted: The sorted list of revision data dictionaries."""
-  step_perf_time_avg = 0.0
-  step_build_time_avg = 0.0
-  step_count = 0.0
-  for _, current_data in revision_data_sorted:
-    if current_data['value']:
-      step_perf_time_avg += current_data['perf_time']
-      step_build_time_avg += current_data['build_time']
-      step_count += 1
-  if step_count:
-    step_perf_time_avg = step_perf_time_avg / step_count
-    step_build_time_avg = step_build_time_avg / step_count
-  print
-  print 'Average build time : %s' % datetime.timedelta(
-      seconds=int(step_build_time_avg))
-  print 'Average test time  : %s' % datetime.timedelta(
-      seconds=int(step_perf_time_avg))
-
-
-def _FindOtherRegressions(revision_data_sorted, bad_greater_than_good):
-  """Compiles a list of other possible regressions from the revision data.
-
-  Args:
-    revision_data_sorted: Sorted list of (revision, revision data) pairs.
-    bad_greater_than_good: Whether the result value at the "bad" revision is
-        numerically greater than the result value at the "good" revision.
-
-  Returns:
-    A list of [current_rev, previous_rev, confidence] for other places where
-    there may have been a regression.
-  """
-  other_regressions = []
-  previous_values = []
-  previous_id = None
-  for current_id, current_data in revision_data_sorted:
-    current_values = current_data['value']
-    if current_values:
-      current_values = current_values['values']
-      if previous_values:
-        confidence = ConfidenceScore(previous_values, [current_values])
-        mean_of_prev_runs = math_utils.Mean(sum(previous_values, []))
-        mean_of_current_runs = math_utils.Mean(current_values)
-
-        # Check that the potential regression is in the same direction as
-        # the overall regression. If the mean of the previous runs < the
-        # mean of the current runs, this local regression is in same
-        # direction.
-        prev_less_than_current = mean_of_prev_runs < mean_of_current_runs
-        is_same_direction = (prev_less_than_current if
-            bad_greater_than_good else not prev_less_than_current)
-
-        # Only report potential regressions with high confidence.
-        if is_same_direction and confidence > 50:
-          other_regressions.append([current_id, previous_id, confidence])
-      previous_values.append(current_values)
-      previous_id = current_id
-  return other_regressions
-
-
-class BisectPerformanceMetrics(object):
-  """This class contains functionality to perform a bisection of a range of
-  revisions to narrow down where performance regressions may have occurred.
-
-  The main entry-point is the Run method.
-  """
-
-  def __init__(self, source_control, opts):
-    super(BisectPerformanceMetrics, self).__init__()
-
-    self.opts = opts
-    self.source_control = source_control
-    self.src_cwd = os.getcwd()
-    self.cros_cwd = os.path.join(os.getcwd(), '..', 'cros')
-    self.depot_cwd = {}
-    self.cleanup_commands = []
-    self.warnings = []
-    self.builder = builder.Builder.FromOpts(opts)
-
-    for d in DEPOT_NAMES:
-      # The working directory of each depot is just the path to the depot, but
-      # since we're already in 'src', we can skip that part.
-
-      self.depot_cwd[d] = os.path.join(
-          self.src_cwd, DEPOT_DEPS_NAME[d]['src'][4:])
-
-  def PerformCleanup(self):
-    """Performs cleanup when script is finished."""
-    os.chdir(self.src_cwd)
-    for c in self.cleanup_commands:
-      if c[0] == 'mv':
-        shutil.move(c[1], c[2])
-      else:
-        assert False, 'Invalid cleanup command.'
-
-  def GetRevisionList(self, depot, bad_revision, good_revision):
-    """Retrieves a list of all the commits between the bad revision and
-    last known good revision."""
-
-    revision_work_list = []
-
-    if depot == 'cros':
-      revision_range_start = good_revision
-      revision_range_end = bad_revision
-
-      cwd = os.getcwd()
-      self.ChangeToDepotWorkingDirectory('cros')
-
-      # Print the commit timestamps for every commit in the revision time
-      # range. We'll sort them and bisect by that. There is a remote chance that
-      # 2 (or more) commits will share the exact same timestamp, but it's
-      # probably safe to ignore that case.
-      cmd = ['repo', 'forall', '-c',
-          'git log --format=%%ct --before=%d --after=%d' % (
-          revision_range_end, revision_range_start)]
-      output, return_code = bisect_utils.RunProcessAndRetrieveOutput(cmd)
-
-      assert not return_code, ('An error occurred while running '
-                               '"%s"' % ' '.join(cmd))
-
-      os.chdir(cwd)
-
-      revision_work_list = list(set(
-          [int(o) for o in output.split('\n') if bisect_utils.IsStringInt(o)]))
-      revision_work_list = sorted(revision_work_list, reverse=True)
-    else:
-      cwd = self._GetDepotDirectory(depot)
-      revision_work_list = self.source_control.GetRevisionList(bad_revision,
-          good_revision, cwd=cwd)
-
-    return revision_work_list
-
-  def _GetV8BleedingEdgeFromV8TrunkIfMappable(self, revision):
-    commit_position = self.source_control.GetCommitPosition(revision)
-
-    if bisect_utils.IsStringInt(commit_position):
-      # V8 is tricky to bisect, in that there are only a few instances when
-      # we can dive into bleeding_edge and get back a meaningful result.
-      # Try to detect a V8 "business as usual" case, which is when:
-      #  1. trunk revision N has description "Version X.Y.Z"
-      #  2. bleeding_edge revision (N-1) has description "Prepare push to
-      #     trunk. Now working on X.Y.(Z+1)."
-      #
-      # As of 01/24/2014, V8 trunk descriptions are formatted:
-      # "Version 3.X.Y (based on bleeding_edge revision rZ)"
-      # So we can just try parsing that out first and fall back to the old way.
-      v8_dir = self._GetDepotDirectory('v8')
-      v8_bleeding_edge_dir = self._GetDepotDirectory('v8_bleeding_edge')
-
-      revision_info = self.source_control.QueryRevisionInfo(revision,
-          cwd=v8_dir)
-
-      version_re = re.compile("Version (?P<values>[0-9,.]+)")
-
-      regex_results = version_re.search(revision_info['subject'])
-
-      if regex_results:
-        git_revision = None
-
-        # Look for "based on bleeding_edge" and parse out revision
-        if 'based on bleeding_edge' in revision_info['subject']:
-          try:
-            bleeding_edge_revision = revision_info['subject'].split(
-                'bleeding_edge revision r')[1]
-            bleeding_edge_revision = int(bleeding_edge_revision.split(')')[0])
-            git_revision = self.source_control.ResolveToRevision(
-                bleeding_edge_revision, 'v8_bleeding_edge', DEPOT_DEPS_NAME, 1,
-                cwd=v8_bleeding_edge_dir)
-            return git_revision
-          except (IndexError, ValueError):
-            pass
-
-        if not git_revision:
-          # Wasn't successful, try the old way of looking for "Prepare push to"
-          git_revision = self.source_control.ResolveToRevision(
-              int(commit_position) - 1, 'v8_bleeding_edge', DEPOT_DEPS_NAME, -1,
-              cwd=v8_bleeding_edge_dir)
-
-          if git_revision:
-            revision_info = self.source_control.QueryRevisionInfo(git_revision,
-                cwd=v8_bleeding_edge_dir)
-
-            if 'Prepare push to trunk' in revision_info['subject']:
-              return git_revision
-    return None
-
-  def _GetNearestV8BleedingEdgeFromTrunk(self, revision, search_forward=True):
-    cwd = self._GetDepotDirectory('v8')
-    cmd = ['log', '--format=%ct', '-1', revision]
-    output = bisect_utils.CheckRunGit(cmd, cwd=cwd)
-    commit_time = int(output)
-    commits = []
-
-    if search_forward:
-      cmd = ['log', '--format=%H', '-10', '--after=%d' % commit_time,
-          'origin/master']
-      output = bisect_utils.CheckRunGit(cmd, cwd=cwd)
-      output = output.split()
-      commits = output
-      commits = reversed(commits)
-    else:
-      cmd = ['log', '--format=%H', '-10', '--before=%d' % commit_time,
-          'origin/master']
-      output = bisect_utils.CheckRunGit(cmd, cwd=cwd)
-      output = output.split()
-      commits = output
-
-    bleeding_edge_revision = None
-
-    for c in commits:
-      bleeding_edge_revision = self._GetV8BleedingEdgeFromV8TrunkIfMappable(c)
-      if bleeding_edge_revision:
-        break
-
-    return bleeding_edge_revision
-
-  def _ParseRevisionsFromDEPSFile(self, depot):
-    """Parses the local DEPS file to determine blink/skia/v8 revisions which may
-    be needed if the bisect recurses into those depots later.
-
-    Args:
-      depot: Name of depot being bisected.
-
-    Returns:
-      A dict in the format {depot:revision} if successful, otherwise None.
-    """
-    try:
-      deps_data = {
-          'Var': lambda _: deps_data["vars"][_],
-          'From': lambda *args: None,
-      }
-
-      deps_file = bisect_utils.FILE_DEPS_GIT
-      if not os.path.exists(deps_file):
-        deps_file = bisect_utils.FILE_DEPS
-      execfile(deps_file, {}, deps_data)
-      deps_data = deps_data['deps']
-
-      rxp = re.compile(".git@(?P<revision>[a-fA-F0-9]+)")
-      results = {}
-      for depot_name, depot_data in DEPOT_DEPS_NAME.iteritems():
-        if (depot_data.get('platform') and
-            depot_data.get('platform') != os.name):
-          continue
-
-        if (depot_data.get('recurse') and depot in depot_data.get('from')):
-          depot_data_src = depot_data.get('src') or depot_data.get('src_old')
-          src_dir = deps_data.get(depot_data_src)
-          if src_dir:
-            self.depot_cwd[depot_name] = os.path.join(self.src_cwd,
-                                                      depot_data_src[4:])
-            re_results = rxp.search(src_dir)
-            if re_results:
-              results[depot_name] = re_results.group('revision')
-            else:
-              warning_text = ('Could not parse revision for %s while bisecting '
-                              '%s' % (depot_name, depot))
-              if not warning_text in self.warnings:
-                self.warnings.append(warning_text)
-          else:
-            results[depot_name] = None
-      return results
-    except ImportError:
-      deps_file_contents = ReadStringFromFile(deps_file)
-      parse_results = _ParseRevisionsFromDEPSFileManually(deps_file_contents)
-      results = {}
-      for depot_name, depot_revision in parse_results.iteritems():
-        depot_revision = depot_revision.strip('@')
-        print depot_name, depot_revision
-        for current_name, current_data in DEPOT_DEPS_NAME.iteritems():
-          if (current_data.has_key('deps_var') and
-              current_data['deps_var'] == depot_name):
-            src_name = current_name
-            results[src_name] = depot_revision
-            break
-      return results
-
-  def _Get3rdPartyRevisions(self, depot):
-    """Parses the DEPS file to determine WebKit/v8/etc... versions.
-
-    Args:
-      depot: A depot name. Should be in the DEPOT_NAMES list.
-
-    Returns:
-      A dict in the format {depot: revision} if successful, otherwise None.
-    """
-    cwd = os.getcwd()
-    self.ChangeToDepotWorkingDirectory(depot)
-
-    results = {}
-
-    if depot == 'chromium' or depot == 'android-chrome':
-      results = self._ParseRevisionsFromDEPSFile(depot)
-      os.chdir(cwd)
-
-    if depot == 'cros':
-      cmd = [
-          bisect_utils.CROS_SDK_PATH,
-          '--',
-          'portageq-%s' % self.opts.cros_board,
-          'best_visible',
-          '/build/%s' % self.opts.cros_board,
-          'ebuild',
-          CROS_CHROMEOS_PATTERN
-      ]
-      output, return_code = bisect_utils.RunProcessAndRetrieveOutput(cmd)
-
-      assert not return_code, ('An error occurred while running '
-                               '"%s"' % ' '.join(cmd))
-
-      if len(output) > CROS_CHROMEOS_PATTERN:
-        output = output[len(CROS_CHROMEOS_PATTERN):]
-
-      if len(output) > 1:
-        output = output.split('_')[0]
-
-        if len(output) > 3:
-          contents = output.split('.')
-
-          version = contents[2]
-
-          if contents[3] != '0':
-            warningText = ('Chrome version: %s.%s but using %s.0 to bisect.' %
-                           (version, contents[3], version))
-            if not warningText in self.warnings:
-              self.warnings.append(warningText)
-
-          cwd = os.getcwd()
-          self.ChangeToDepotWorkingDirectory('chromium')
-          cmd = ['log', '-1', '--format=%H',
-                 '--author=chrome-release@google.com',
-                 '--grep=to %s' % version, 'origin/master']
-          return_code = bisect_utils.CheckRunGit(cmd)
-          os.chdir(cwd)
-
-          results['chromium'] = output.strip()
-
-    if depot == 'v8':
-      # We can't try to map the trunk revision to bleeding edge yet, because
-      # we don't know which direction to try to search in. Have to wait until
-      # the bisect has narrowed the results down to 2 v8 rolls.
-      results['v8_bleeding_edge'] = None
-
-    return results
-
-  def BackupOrRestoreOutputDirectory(self, restore=False, build_type='Release'):
-    """Backs up or restores build output directory based on restore argument.
-
-    Args:
-      restore: Indicates whether to restore or backup. Default is False(Backup)
-      build_type: Target build type ('Release', 'Debug', 'Release_x64' etc.)
-
-    Returns:
-      Path to backup or restored location as string. otherwise None if it fails.
-    """
-    build_dir = os.path.abspath(
-        builder.GetBuildOutputDirectory(self.opts, self.src_cwd))
-    source_dir = os.path.join(build_dir, build_type)
-    destination_dir = os.path.join(build_dir, '%s.bak' % build_type)
-    if restore:
-      source_dir, destination_dir = destination_dir, source_dir
-    if os.path.exists(source_dir):
-      RmTreeAndMkDir(destination_dir, skip_makedir=True)
-      shutil.move(source_dir, destination_dir)
-      return destination_dir
-    return None
-
-  def GetBuildArchiveForRevision(self, revision, gs_bucket, target_arch,
-                                 patch_sha, out_dir):
-    """Checks and downloads build archive for a given revision.
-
-    Checks for build archive with Git hash or SVN revision. If either of the
-    file exists, then downloads the archive file.
-
-    Args:
-      revision: A Git hash revision.
-      gs_bucket: Cloud storage bucket name
-      target_arch: 32 or 64 bit build target
-      patch: A DEPS patch (used while bisecting 3rd party repositories).
-      out_dir: Build output directory where downloaded file is stored.
-
-    Returns:
-      Downloaded archive file path if exists, otherwise None.
-    """
-    # Source archive file path on cloud storage using Git revision.
-    source_file = GetRemoteBuildPath(
-        revision, self.opts.target_platform, target_arch, patch_sha)
-    downloaded_archive = FetchFromCloudStorage(gs_bucket, source_file, out_dir)
-    if not downloaded_archive:
-      # Get commit position for the given SHA.
-      commit_position = self.source_control.GetCommitPosition(revision)
-      if commit_position:
-        # Source archive file path on cloud storage using SVN revision.
-        source_file = GetRemoteBuildPath(
-            commit_position, self.opts.target_platform, target_arch, patch_sha)
-        return FetchFromCloudStorage(gs_bucket, source_file, out_dir)
-    return downloaded_archive
-
-  def DownloadCurrentBuild(self, revision, build_type='Release', patch=None):
-    """Downloads the build archive for the given revision.
-
-    Args:
-      revision: The Git revision to download or build.
-      build_type: Target build type ('Release', 'Debug', 'Release_x64' etc.)
-      patch: A DEPS patch (used while bisecting 3rd party repositories).
-
-    Returns:
-      True if download succeeds, otherwise False.
-    """
-    patch_sha = None
-    if patch:
-      # Get the SHA of the DEPS changes patch.
-      patch_sha = GetSHA1HexDigest(patch)
-
-      # Update the DEPS changes patch with a patch to create a new file named
-      # 'DEPS.sha' and add patch_sha evaluated above to it.
-      patch = '%s\n%s' % (patch, DEPS_SHA_PATCH % {'deps_sha': patch_sha})
-
-    # Get Build output directory
-    abs_build_dir = os.path.abspath(
-        builder.GetBuildOutputDirectory(self.opts, self.src_cwd))
-
-    fetch_build_func = lambda: self.GetBuildArchiveForRevision(
-      revision, self.opts.gs_bucket, self.opts.target_arch,
-      patch_sha, abs_build_dir)
-
-    # Downloaded archive file path, downloads build archive for given revision.
-    downloaded_file = fetch_build_func()
-
-    # When build archive doesn't exists, post a build request to tryserver
-    # and wait for the build to be produced.
-    if not downloaded_file:
-      downloaded_file = self.PostBuildRequestAndWait(
-          revision, fetch_build=fetch_build_func, patch=patch)
-      if not downloaded_file:
-        return False
-
-    # Generic name for the archive, created when archive file is extracted.
-    output_dir = os.path.join(
-        abs_build_dir, GetZipFileName(target_arch=self.opts.target_arch))
-    # Unzip build archive directory.
-    try:
-      RmTreeAndMkDir(output_dir, skip_makedir=True)
-      self.BackupOrRestoreOutputDirectory(restore=False)
-      # Build output directory based on target(e.g. out/Release, out/Debug).
-      target_build_output_dir = os.path.join(abs_build_dir, build_type)
-      ExtractZip(downloaded_file, abs_build_dir)
-      if not os.path.exists(output_dir):
-        # Due to recipe changes, the builds extract folder contains
-        # out/Release instead of full-build-<platform>/Release.
-        if os.path.exists(os.path.join(abs_build_dir, 'out', build_type)):
-          output_dir = os.path.join(abs_build_dir, 'out', build_type)
-        else:
-          raise IOError('Missing extracted folder %s ' % output_dir)
-
-      print 'Moving build from %s to %s' % (
-          output_dir, target_build_output_dir)
-      shutil.move(output_dir, target_build_output_dir)
-      return True
-    except Exception as e:
-      print 'Something went wrong while extracting archive file: %s' % e
-      self.BackupOrRestoreOutputDirectory(restore=True)
-      # Cleanup any leftovers from unzipping.
-      if os.path.exists(output_dir):
-        RmTreeAndMkDir(output_dir, skip_makedir=True)
-    finally:
-      # Delete downloaded archive
-      if os.path.exists(downloaded_file):
-        os.remove(downloaded_file)
-    return False
-
-  def PostBuildRequestAndWait(self, git_revision, fetch_build, patch=None):
-    """POSTs the build request job to the try server instance.
-
-    A try job build request is posted to tryserver.chromium.perf master,
-    and waits for the binaries to be produced and archived on cloud storage.
-    Once the build is ready and stored onto cloud, build archive is downloaded
-    into the output folder.
-
-    Args:
-      git_revision: A Git hash revision.
-      fetch_build: Function to check and download build from cloud storage.
-      patch: A DEPS patch (used while bisecting 3rd party repositories).
-
-    Returns:
-      Downloaded archive file path when requested build exists and download is
-      successful, otherwise None.
-    """
-    def GetBuilderNameAndBuildTime(target_platform, target_arch='ia32'):
-      """Gets builder bot name and build time in seconds based on platform."""
-      # Bot names should match the one listed in tryserver.chromium's
-      # master.cfg which produces builds for bisect.
-      if bisect_utils.IsWindowsHost():
-        if bisect_utils.Is64BitWindows() and target_arch == 'x64':
-          return ('win_perf_bisect_builder', MAX_WIN_BUILD_TIME)
-        return ('win_perf_bisect_builder', MAX_WIN_BUILD_TIME)
-      if bisect_utils.IsLinuxHost():
-        if target_platform == 'android':
-          return ('android_perf_bisect_builder', MAX_LINUX_BUILD_TIME)
-        return ('linux_perf_bisect_builder', MAX_LINUX_BUILD_TIME)
-      if bisect_utils.IsMacHost():
-        return ('mac_perf_bisect_builder', MAX_MAC_BUILD_TIME)
-      raise NotImplementedError('Unsupported Platform "%s".' % sys.platform)
-    if not fetch_build:
-      return False
-
-    bot_name, build_timeout = GetBuilderNameAndBuildTime(
-       self.opts.target_platform, self.opts.target_arch)
-    builder_host = self.opts.builder_host
-    builder_port = self.opts.builder_port
-    # Create a unique ID for each build request posted to try server builders.
-    # This ID is added to "Reason" property of the build.
-    build_request_id = GetSHA1HexDigest(
-        '%s-%s-%s' % (git_revision, patch, time.time()))
-
-    # Creates a try job description.
-    # Always use Git hash to post build request since Commit positions are
-    # not supported by builders to build.
-    job_args = {
-        'revision': 'src@%s' % git_revision,
-        'bot': bot_name,
-        'name': build_request_id,
-    }
-    # Update patch information if supplied.
-    if patch:
-      job_args['patch'] = patch
-    # Posts job to build the revision on the server.
-    if request_build.PostTryJob(builder_host, builder_port, job_args):
-      target_file, error_msg = _WaitUntilBuildIsReady(
-          fetch_build, bot_name, builder_host, builder_port, build_request_id,
-          build_timeout)
-      if not target_file:
-        print '%s [revision: %s]' % (error_msg, git_revision)
-        return None
-      return target_file
-    print 'Failed to post build request for revision: [%s]' % git_revision
-    return None
-
-  def IsDownloadable(self, depot):
-    """Checks if build can be downloaded based on target platform and depot."""
-    if (self.opts.target_platform in ['chromium', 'android'] and
-        self.opts.gs_bucket):
-      return (depot == 'chromium' or
-              'chromium' in DEPOT_DEPS_NAME[depot]['from'] or
-              'v8' in DEPOT_DEPS_NAME[depot]['from'])
-    return False
-
-  def UpdateDepsContents(self, deps_contents, depot, git_revision, deps_key):
-    """Returns modified version of DEPS file contents.
-
-    Args:
-      deps_contents: DEPS file content.
-      depot: Current depot being bisected.
-      git_revision: A git hash to be updated in DEPS.
-      deps_key: Key in vars section of DEPS file to be searched.
-
-    Returns:
-      Updated DEPS content as string if deps key is found, otherwise None.
-    """
-    # Check whether the depot and revision pattern in DEPS file vars
-    # e.g. for webkit the format is "webkit_revision": "12345".
-    deps_revision = re.compile(r'(?<="%s": ")([0-9]+)(?=")' % deps_key,
-                               re.MULTILINE)
-    new_data = None
-    if re.search(deps_revision, deps_contents):
-      commit_position = self.source_control.GetCommitPosition(
-          git_revision, self._GetDepotDirectory(depot))
-      if not commit_position:
-        print 'Could not determine commit position for %s' % git_revision
-        return None
-      # Update the revision information for the given depot
-      new_data = re.sub(deps_revision, str(commit_position), deps_contents)
-    else:
-      # Check whether the depot and revision pattern in DEPS file vars
-      # e.g. for webkit the format is "webkit_revision": "559a6d4ab7a84c539..".
-      deps_revision = re.compile(
-          r'(?<=["\']%s["\']: ["\'])([a-fA-F0-9]{40})(?=["\'])' % deps_key,
-          re.MULTILINE)
-      if re.search(deps_revision, deps_contents):
-        new_data = re.sub(deps_revision, git_revision, deps_contents)
-    if new_data:
-      # For v8_bleeding_edge revisions change V8 branch in order
-      # to fetch bleeding edge revision.
-      if depot == 'v8_bleeding_edge':
-        new_data = _UpdateV8Branch(new_data)
-        if not new_data:
-          return None
-    return new_data
-
-  def UpdateDeps(self, revision, depot, deps_file):
-    """Updates DEPS file with new revision of dependency repository.
-
-    This method search DEPS for a particular pattern in which depot revision
-    is specified (e.g "webkit_revision": "123456"). If a match is found then
-    it resolves the given git hash to SVN revision and replace it in DEPS file.
-
-    Args:
-      revision: A git hash revision of the dependency repository.
-      depot: Current depot being bisected.
-      deps_file: Path to DEPS file.
-
-    Returns:
-      True if DEPS file is modified successfully, otherwise False.
-    """
-    if not os.path.exists(deps_file):
-      return False
-
-    deps_var = DEPOT_DEPS_NAME[depot]['deps_var']
-    # Don't update DEPS file if deps_var is not set in DEPOT_DEPS_NAME.
-    if not deps_var:
-      print 'DEPS update not supported for Depot: %s', depot
-      return False
-
-    # Hack for Angle repository. In the DEPS file, "vars" dictionary variable
-    # contains "angle_revision" key that holds git hash instead of SVN revision.
-    # And sometime "angle_revision" key is not specified in "vars" variable.
-    # In such cases check, "deps" dictionary variable that matches
-    # angle.git@[a-fA-F0-9]{40}$ and replace git hash.
-    if depot == 'angle':
-      return _UpdateDEPSForAngle(revision, depot, deps_file)
-
-    try:
-      deps_contents = ReadStringFromFile(deps_file)
-      updated_deps_content = self.UpdateDepsContents(
-          deps_contents, depot, revision, deps_var)
-      # Write changes to DEPS file
-      if updated_deps_content:
-        WriteStringToFile(updated_deps_content, deps_file)
-        return True
-    except IOError, e:
-      print 'Something went wrong while updating DEPS file. [%s]' % e
-    return False
-
-  def CreateDEPSPatch(self, depot, revision):
-    """Modifies DEPS and returns diff as text.
-
-    Args:
-      depot: Current depot being bisected.
-      revision: A git hash revision of the dependency repository.
-
-    Returns:
-      A tuple with git hash of chromium revision and DEPS patch text.
-    """
-    deps_file_path = os.path.join(self.src_cwd, bisect_utils.FILE_DEPS)
-    if not os.path.exists(deps_file_path):
-      raise RuntimeError('DEPS file does not exists.[%s]' % deps_file_path)
-    # Get current chromium revision (git hash).
-    cmd = ['rev-parse', 'HEAD']
-    chromium_sha = bisect_utils.CheckRunGit(cmd).strip()
-    if not chromium_sha:
-      raise RuntimeError('Failed to determine Chromium revision for %s' %
-                         revision)
-    if ('chromium' in DEPOT_DEPS_NAME[depot]['from'] or
-        'v8' in DEPOT_DEPS_NAME[depot]['from']):
-      # Checkout DEPS file for the current chromium revision.
-      if self.source_control.CheckoutFileAtRevision(
-          bisect_utils.FILE_DEPS, chromium_sha, cwd=self.src_cwd):
-        if self.UpdateDeps(revision, depot, deps_file_path):
-          diff_command = [
-              'diff',
-              '--src-prefix=src/',
-              '--dst-prefix=src/',
-              '--no-ext-diff',
-               bisect_utils.FILE_DEPS,
-          ]
-          diff_text = bisect_utils.CheckRunGit(diff_command, cwd=self.src_cwd)
-          return (chromium_sha, ChangeBackslashToSlashInPatch(diff_text))
-        else:
-          raise RuntimeError(
-              'Failed to update DEPS file for chromium: [%s]' % chromium_sha)
-      else:
-        raise RuntimeError(
-            'DEPS checkout Failed for chromium revision : [%s]' % chromium_sha)
-    return (None, None)
-
-  def BuildCurrentRevision(self, depot, revision=None):
-    """Builds chrome and performance_ui_tests on the current revision.
-
-    Returns:
-      True if the build was successful.
-    """
-    if self.opts.debug_ignore_build:
-      return True
-
-    build_success = False
-    cwd = os.getcwd()
-    os.chdir(self.src_cwd)
-    # Fetch build archive for the given revision from the cloud storage when
-    # the storage bucket is passed.
-    if self.IsDownloadable(depot) and revision:
-      deps_patch = None
-      if depot != 'chromium':
-        # Create a DEPS patch with new revision for dependency repository.
-        revision, deps_patch = self.CreateDEPSPatch(depot, revision)
-      if self.DownloadCurrentBuild(revision, patch=deps_patch):
-        if deps_patch:
-          # Reverts the changes to DEPS file.
-          self.source_control.CheckoutFileAtRevision(
-              bisect_utils.FILE_DEPS, revision, cwd=self.src_cwd)
-        build_success = True
-    else:
-      # These codes are executed when bisect bots builds binaries locally.
-      build_success = self.builder.Build(depot, self.opts)
-    os.chdir(cwd)
-    return build_success
-
-  def RunGClientHooks(self):
-    """Runs gclient with runhooks command.
-
-    Returns:
-      True if gclient reports no errors.
-    """
-    if self.opts.debug_ignore_build:
-      return True
-    return not bisect_utils.RunGClient(['runhooks'], cwd=self.src_cwd)
-
-  def _IsBisectModeUsingMetric(self):
-    return self.opts.bisect_mode in [BISECT_MODE_MEAN, BISECT_MODE_STD_DEV]
-
-  def _IsBisectModeReturnCode(self):
-    return self.opts.bisect_mode in [BISECT_MODE_RETURN_CODE]
-
-  def _IsBisectModeStandardDeviation(self):
-    return self.opts.bisect_mode in [BISECT_MODE_STD_DEV]
-
-  def GetCompatibleCommand(self, command_to_run, revision, depot):
-    # Prior to crrev.com/274857 *only* android-chromium-testshell
-    # Then until crrev.com/276628 *both* (android-chromium-testshell and
-    # android-chrome-shell) work. After that rev 276628 *only*
-    # android-chrome-shell works. bisect-perf-regression.py script should
-    # handle these cases and set appropriate browser type based on revision.
-    if self.opts.target_platform in ['android']:
-      # When its a third_party depot, get the chromium revision.
-      if depot != 'chromium':
-        revision = bisect_utils.CheckRunGit(
-            ['rev-parse', 'HEAD'], cwd=self.src_cwd).strip()
-      commit_position = self.source_control.GetCommitPosition(revision,
-                                                              cwd=self.src_cwd)
-      if not commit_position:
-        return command_to_run
-      cmd_re = re.compile('--browser=(?P<browser_type>\S+)')
-      matches = cmd_re.search(command_to_run)
-      if bisect_utils.IsStringInt(commit_position) and matches:
-        cmd_browser = matches.group('browser_type')
-        if commit_position <= 274857 and cmd_browser == 'android-chrome-shell':
-          return command_to_run.replace(cmd_browser,
-                                        'android-chromium-testshell')
-        elif (commit_position >= 276628 and
-              cmd_browser == 'android-chromium-testshell'):
-          return command_to_run.replace(cmd_browser,
-                                        'android-chrome-shell')
-    return command_to_run
-
-  def RunPerformanceTestAndParseResults(
-      self, command_to_run, metric, reset_on_first_run=False,
-      upload_on_last_run=False, results_label=None):
-    """Runs a performance test on the current revision and parses the results.
-
-    Args:
-      command_to_run: The command to be run to execute the performance test.
-      metric: The metric to parse out from the results of the performance test.
-          This is the result chart name and trace name, separated by slash.
-          May be None for perf try jobs.
-      reset_on_first_run: If True, pass the flag --reset-results on first run.
-      upload_on_last_run: If True, pass the flag --upload-results on last run.
-      results_label: A value for the option flag --results-label.
-          The arguments reset_on_first_run, upload_on_last_run and results_label
-          are all ignored if the test is not a Telemetry test.
-
-    Returns:
-      (values dict, 0) if --debug_ignore_perf_test was passed.
-      (values dict, 0, test output) if the test was run successfully.
-      (error message, -1) if the test couldn't be run.
-      (error message, -1, test output) if the test ran but there was an error.
-    """
-    success_code, failure_code = 0, -1
-
-    if self.opts.debug_ignore_perf_test:
-      fake_results = {
-          'mean': 0.0,
-          'std_err': 0.0,
-          'std_dev': 0.0,
-          'values': [0.0]
-      }
-      return (fake_results, success_code)
-
-    # For Windows platform set posix=False, to parse windows paths correctly.
-    # On Windows, path separators '\' or '\\' are replace by '' when posix=True,
-    # refer to http://bugs.python.org/issue1724822. By default posix=True.
-    args = shlex.split(command_to_run, posix=not bisect_utils.IsWindowsHost())
-
-    if not _GenerateProfileIfNecessary(args):
-      err_text = 'Failed to generate profile for performance test.'
-      return (err_text, failure_code)
-
-    # If running a Telemetry test for Chrome OS, insert the remote IP and
-    # identity parameters.
-    is_telemetry = bisect_utils.IsTelemetryCommand(command_to_run)
-    if self.opts.target_platform == 'cros' and is_telemetry:
-      args.append('--remote=%s' % self.opts.cros_remote_ip)
-      args.append('--identity=%s' % bisect_utils.CROS_TEST_KEY_PATH)
-
-    start_time = time.time()
-
-    metric_values = []
-    output_of_all_runs = ''
-    for i in xrange(self.opts.repeat_test_count):
-      # Can ignore the return code since if the tests fail, it won't return 0.
-      current_args = copy.copy(args)
-      if is_telemetry:
-        if i == 0 and reset_on_first_run:
-          current_args.append('--reset-results')
-        elif i == self.opts.repeat_test_count - 1 and upload_on_last_run:
-          current_args.append('--upload-results')
-        if results_label:
-          current_args.append('--results-label=%s' % results_label)
-      try:
-        output, return_code = bisect_utils.RunProcessAndRetrieveOutput(
-            current_args, cwd=self.src_cwd)
-      except OSError, e:
-        if e.errno == errno.ENOENT:
-          err_text  = ('Something went wrong running the performance test. '
-                       'Please review the command line:\n\n')
-          if 'src/' in ' '.join(args):
-            err_text += ('Check that you haven\'t accidentally specified a '
-                         'path with src/ in the command.\n\n')
-          err_text += ' '.join(args)
-          err_text += '\n'
-
-          return (err_text, failure_code)
-        raise
-
-      output_of_all_runs += output
-      if self.opts.output_buildbot_annotations:
-        print output
-
-      if metric and self._IsBisectModeUsingMetric():
-        metric_values += _ParseMetricValuesFromOutput(metric, output)
-        # If we're bisecting on a metric (ie, changes in the mean or
-        # standard deviation) and no metric values are produced, bail out.
-        if not metric_values:
-          break
-      elif self._IsBisectModeReturnCode():
-        metric_values.append(return_code)
-
-      elapsed_minutes = (time.time() - start_time) / 60.0
-      if elapsed_minutes >= self.opts.max_time_minutes:
-        break
-
-    if metric and len(metric_values) == 0:
-      err_text = 'Metric %s was not found in the test output.' % metric
-      # TODO(qyearsley): Consider also getting and displaying a list of metrics
-      # that were found in the output here.
-      return (err_text, failure_code, output_of_all_runs)
-
-    # If we're bisecting on return codes, we're really just looking for zero vs
-    # non-zero.
-    values = {}
-    if self._IsBisectModeReturnCode():
-      # If any of the return codes is non-zero, output 1.
-      overall_return_code = 0 if (
-          all(current_value == 0 for current_value in metric_values)) else 1
-
-      values = {
-          'mean': overall_return_code,
-          'std_err': 0.0,
-          'std_dev': 0.0,
-          'values': metric_values,
-      }
-
-      print 'Results of performance test: Command returned with %d' % (
-          overall_return_code)
-      print
-    elif metric:
-      # Need to get the average value if there were multiple values.
-      truncated_mean = math_utils.TruncatedMean(
-          metric_values, self.opts.truncate_percent)
-      standard_err = math_utils.StandardError(metric_values)
-      standard_dev = math_utils.StandardDeviation(metric_values)
-
-      if self._IsBisectModeStandardDeviation():
-        metric_values = [standard_dev]
-
-      values = {
-          'mean': truncated_mean,
-          'std_err': standard_err,
-          'std_dev': standard_dev,
-          'values': metric_values,
-      }
-
-      print 'Results of performance test: %12f %12f' % (
-          truncated_mean, standard_err)
-      print
-    return (values, success_code, output_of_all_runs)
-
-  def _FindAllRevisionsToSync(self, revision, depot):
-    """Finds all dependent revisions and depots that need to be synced.
-
-    For example skia is broken up into 3 git mirrors over skia/src,
-    skia/gyp, and skia/include. To sync skia/src properly, one has to find
-    the proper revisions in skia/gyp and skia/include.
-
-    This is only useful in the git workflow, as an SVN depot may be split into
-    multiple mirrors.
-
-    Args:
-      revision: The revision to sync to.
-      depot: The depot in use at the moment (probably skia).
-
-    Returns:
-      A list of [depot, revision] pairs that need to be synced.
-    """
-    revisions_to_sync = [[depot, revision]]
-
-    is_base = ((depot == 'chromium') or (depot == 'cros') or
-        (depot == 'android-chrome'))
-
-    # Some SVN depots were split into multiple git depots, so we need to
-    # figure out for each mirror which git revision to grab. There's no
-    # guarantee that the SVN revision will exist for each of the dependent
-    # depots, so we have to grep the git logs and grab the next earlier one.
-    if (not is_base
-        and DEPOT_DEPS_NAME[depot]['depends']
-        and self.source_control.IsGit()):
-      commit_position = self.source_control.GetCommitPosition(revision)
-
-      for d in DEPOT_DEPS_NAME[depot]['depends']:
-        self.ChangeToDepotWorkingDirectory(d)
-
-        dependant_rev = self.source_control.ResolveToRevision(
-            commit_position, d, DEPOT_DEPS_NAME, -1000)
-
-        if dependant_rev:
-          revisions_to_sync.append([d, dependant_rev])
-
-      num_resolved = len(revisions_to_sync)
-      num_needed = len(DEPOT_DEPS_NAME[depot]['depends'])
-
-      self.ChangeToDepotWorkingDirectory(depot)
-
-      if not ((num_resolved - 1) == num_needed):
-        return None
-
-    return revisions_to_sync
-
-  def PerformPreBuildCleanup(self):
-    """Performs cleanup between runs."""
-    print 'Cleaning up between runs.'
-    print
-
-    # Leaving these .pyc files around between runs may disrupt some perf tests.
-    for (path, _, files) in os.walk(self.src_cwd):
-      for cur_file in files:
-        if cur_file.endswith('.pyc'):
-          path_to_file = os.path.join(path, cur_file)
-          os.remove(path_to_file)
-
-  def PerformCrosChrootCleanup(self):
-    """Deletes the chroot.
-
-    Returns:
-      True if successful.
-    """
-    cwd = os.getcwd()
-    self.ChangeToDepotWorkingDirectory('cros')
-    cmd = [bisect_utils.CROS_SDK_PATH, '--delete']
-    return_code = bisect_utils.RunProcess(cmd)
-    os.chdir(cwd)
-    return not return_code
-
-  def CreateCrosChroot(self):
-    """Creates a new chroot.
-
-    Returns:
-      True if successful.
-    """
-    cwd = os.getcwd()
-    self.ChangeToDepotWorkingDirectory('cros')
-    cmd = [bisect_utils.CROS_SDK_PATH, '--create']
-    return_code = bisect_utils.RunProcess(cmd)
-    os.chdir(cwd)
-    return not return_code
-
-  def _PerformPreSyncCleanup(self, depot):
-    """Performs any necessary cleanup before syncing.
-
-    Args:
-      depot: Depot name.
-
-    Returns:
-      True if successful.
-    """
-    if depot == 'chromium' or depot == 'android-chrome':
-      # Removes third_party/libjingle. At some point, libjingle was causing
-      # issues syncing when using the git workflow (crbug.com/266324).
-      os.chdir(self.src_cwd)
-      if not bisect_utils.RemoveThirdPartyDirectory('libjingle'):
-        return False
-      # Removes third_party/skia. At some point, skia was causing
-      # issues syncing when using the git workflow (crbug.com/377951).
-      if not bisect_utils.RemoveThirdPartyDirectory('skia'):
-        return False
-    elif depot == 'cros':
-      return self.PerformCrosChrootCleanup()
-    return True
-
-  def _RunPostSync(self, depot):
-    """Performs any work after syncing.
-
-    Args:
-      depot: Depot name.
-
-    Returns:
-      True if successful.
-    """
-    if self.opts.target_platform == 'android':
-      if not builder.SetupAndroidBuildEnvironment(self.opts,
-          path_to_src=self.src_cwd):
-        return False
-
-    if depot == 'cros':
-      return self.CreateCrosChroot()
-    else:
-      return self.RunGClientHooks()
-    return True
-
-  def ShouldSkipRevision(self, depot, revision):
-    """Checks whether a particular revision can be safely skipped.
-
-    Some commits can be safely skipped (such as a DEPS roll), since the tool
-    is git based those changes would have no effect.
-
-    Args:
-      depot: The depot being bisected.
-      revision: Current revision we're synced to.
-
-    Returns:
-      True if we should skip building/testing this revision.
-    """
-    if depot == 'chromium':
-      if self.source_control.IsGit():
-        cmd = ['diff-tree', '--no-commit-id', '--name-only', '-r', revision]
-        output = bisect_utils.CheckRunGit(cmd)
-
-        files = output.splitlines()
-
-        if len(files) == 1 and files[0] == 'DEPS':
-          return True
-
-    return False
-
-  def RunTest(self, revision, depot, command, metric, skippable=False):
-    """Performs a full sync/build/run of the specified revision.
-
-    Args:
-      revision: The revision to sync to.
-      depot: The depot that's being used at the moment (src, webkit, etc.)
-      command: The command to execute the performance test.
-      metric: The performance metric being tested.
-
-    Returns:
-      On success, a tuple containing the results of the performance test.
-      Otherwise, a tuple with the error message.
-    """
-    # Decide which sync program to use.
-    sync_client = None
-    if depot == 'chromium' or depot == 'android-chrome':
-      sync_client = 'gclient'
-    elif depot == 'cros':
-      sync_client = 'repo'
-
-    # Decide what depots will need to be synced to what revisions.
-    revisions_to_sync = self._FindAllRevisionsToSync(revision, depot)
-    if not revisions_to_sync:
-      return ('Failed to resolve dependent depots.', BUILD_RESULT_FAIL)
-
-    if not self._PerformPreSyncCleanup(depot):
-      return ('Failed to perform pre-sync cleanup.', BUILD_RESULT_FAIL)
-
-    # Do the syncing for all depots.
-    if not self.opts.debug_ignore_sync:
-      if not self._SyncAllRevisions(revisions_to_sync, sync_client):
-        return ('Failed to sync: [%s]' % str(revision), BUILD_RESULT_FAIL)
-
-     # Try to do any post-sync steps. This may include "gclient runhooks".
-    if not self._RunPostSync(depot):
-      return ('Failed to run [gclient runhooks].', BUILD_RESULT_FAIL)
-
-    # Skip this revision if it can be skipped.
-    if skippable and self.ShouldSkipRevision(depot, revision):
-      return ('Skipped revision: [%s]' % str(revision),
-              BUILD_RESULT_SKIPPED)
-
-    # Obtain a build for this revision. This may be done by requesting a build
-    # from another builder, waiting for it and downloading it.
-    start_build_time = time.time()
-    build_success = self.BuildCurrentRevision(depot, revision)
-    if not build_success:
-      return ('Failed to build revision: [%s]' % str(revision),
-              BUILD_RESULT_FAIL)
-    after_build_time = time.time()
-
-    # Possibly alter the command.
-    command = self.GetCompatibleCommand(command, revision, depot)
-
-    # Run the command and get the results.
-    results = self.RunPerformanceTestAndParseResults(command, metric)
-
-    # Restore build output directory once the tests are done, to avoid
-    # any discrepancies.
-    if self.IsDownloadable(depot) and revision:
-      self.BackupOrRestoreOutputDirectory(restore=True)
-
-    # A value other than 0 indicates that the test couldn't be run, and results
-    # should also include an error message.
-    if results[1] != 0:
-      return results
-
-    external_revisions = self._Get3rdPartyRevisions(depot)
-
-    if not external_revisions is None:
-      return (results[0], results[1], external_revisions,
-          time.time() - after_build_time, after_build_time -
-          start_build_time)
-    else:
-      return ('Failed to parse DEPS file for external revisions.',
-               BUILD_RESULT_FAIL)
-
-  def _SyncAllRevisions(self, revisions_to_sync, sync_client):
-    """Syncs multiple depots to particular revisions.
-
-    Args:
-      revisions_to_sync: A list of (depot, revision) pairs to be synced.
-      sync_client: Program used to sync, e.g. "gclient", "repo". Can be None.
-
-    Returns:
-      True if successful, False otherwise.
-    """
-    for depot, revision in revisions_to_sync:
-      self.ChangeToDepotWorkingDirectory(depot)
-
-      if sync_client:
-        self.PerformPreBuildCleanup()
-
-      # When using gclient to sync, you need to specify the depot you
-      # want so that all the dependencies sync properly as well.
-      # i.e. gclient sync src@<SHA1>
-      if sync_client == 'gclient':
-        revision = '%s@%s' % (DEPOT_DEPS_NAME[depot]['src'], revision)
-
-      sync_success = self.source_control.SyncToRevision(revision, sync_client)
-      if not sync_success:
-        return False
-
-    return True
-
-  def _CheckIfRunPassed(self, current_value, known_good_value, known_bad_value):
-    """Given known good and bad values, decide if the current_value passed
-    or failed.
-
-    Args:
-      current_value: The value of the metric being checked.
-      known_bad_value: The reference value for a "failed" run.
-      known_good_value: The reference value for a "passed" run.
-
-    Returns:
-      True if the current_value is closer to the known_good_value than the
-      known_bad_value.
-    """
-    if self.opts.bisect_mode == BISECT_MODE_STD_DEV:
-      dist_to_good_value = abs(current_value['std_dev'] -
-          known_good_value['std_dev'])
-      dist_to_bad_value = abs(current_value['std_dev'] -
-          known_bad_value['std_dev'])
-    else:
-      dist_to_good_value = abs(current_value['mean'] - known_good_value['mean'])
-      dist_to_bad_value = abs(current_value['mean'] - known_bad_value['mean'])
-
-    return dist_to_good_value < dist_to_bad_value
-
-  def _GetDepotDirectory(self, depot_name):
-    if depot_name == 'chromium':
-      return self.src_cwd
-    elif depot_name == 'cros':
-      return self.cros_cwd
-    elif depot_name in DEPOT_NAMES:
-      return self.depot_cwd[depot_name]
-    else:
-      assert False, ('Unknown depot [ %s ] encountered. Possibly a new one '
-                     'was added without proper support?' % depot_name)
-
-  def ChangeToDepotWorkingDirectory(self, depot_name):
-    """Given a depot, changes to the appropriate working directory.
-
-    Args:
-      depot_name: The name of the depot (see DEPOT_NAMES).
-    """
-    os.chdir(self._GetDepotDirectory(depot_name))
-
-  def _FillInV8BleedingEdgeInfo(self, min_revision_data, max_revision_data):
-    r1 = self._GetNearestV8BleedingEdgeFromTrunk(min_revision_data['revision'],
-        search_forward=True)
-    r2 = self._GetNearestV8BleedingEdgeFromTrunk(max_revision_data['revision'],
-        search_forward=False)
-    min_revision_data['external']['v8_bleeding_edge'] = r1
-    max_revision_data['external']['v8_bleeding_edge'] = r2
-
-    if (not self._GetV8BleedingEdgeFromV8TrunkIfMappable(
-            min_revision_data['revision'])
-        or not self._GetV8BleedingEdgeFromV8TrunkIfMappable(
-            max_revision_data['revision'])):
-      self.warnings.append(
-          'Trunk revisions in V8 did not map directly to bleeding_edge. '
-          'Attempted to expand the range to find V8 rolls which did map '
-          'directly to bleeding_edge revisions, but results might not be '
-          'valid.')
-
-  def _FindNextDepotToBisect(
-      self, current_depot, min_revision_data, max_revision_data):
-    """Decides which depot the script should dive into next (if any).
-
-    Args:
-      current_depot: Current depot being bisected.
-      min_revision_data: Data about the earliest revision in the bisect range.
-      max_revision_data: Data about the latest revision in the bisect range.
-
-    Returns:
-      Name of the depot to bisect next, or None.
-    """
-    external_depot = None
-    for next_depot in DEPOT_NAMES:
-      if DEPOT_DEPS_NAME[next_depot].has_key('platform'):
-        if DEPOT_DEPS_NAME[next_depot]['platform'] != os.name:
-          continue
-
-      if not (DEPOT_DEPS_NAME[next_depot]['recurse']
-              and min_revision_data['depot']
-              in DEPOT_DEPS_NAME[next_depot]['from']):
-        continue
-
-      if current_depot == 'v8':
-        # We grab the bleeding_edge info here rather than earlier because we
-        # finally have the revision range. From that we can search forwards and
-        # backwards to try to match trunk revisions to bleeding_edge.
-        self._FillInV8BleedingEdgeInfo(min_revision_data, max_revision_data)
-
-      if (min_revision_data['external'].get(next_depot) ==
-          max_revision_data['external'].get(next_depot)):
-        continue
-
-      if (min_revision_data['external'].get(next_depot) and
-          max_revision_data['external'].get(next_depot)):
-        external_depot = next_depot
-        break
-
-    return external_depot
-
-  def PrepareToBisectOnDepot(
-      self, current_depot, end_revision, start_revision, previous_revision):
-    """Changes to the appropriate directory and gathers a list of revisions
-    to bisect between |start_revision| and |end_revision|.
-
-    Args:
-      current_depot: The depot we want to bisect.
-      end_revision: End of the revision range.
-      start_revision: Start of the revision range.
-      previous_revision: The last revision we synced to on |previous_depot|.
-
-    Returns:
-      A list containing the revisions between |start_revision| and
-      |end_revision| inclusive.
-    """
-    # Change into working directory of external library to run
-    # subsequent commands.
-    self.ChangeToDepotWorkingDirectory(current_depot)
-
-    # V8 (and possibly others) is merged in periodically. Bisecting
-    # this directory directly won't give much good info.
-    if DEPOT_DEPS_NAME[current_depot].has_key('custom_deps'):
-      config_path = os.path.join(self.src_cwd, '..')
-      if bisect_utils.RunGClientAndCreateConfig(self.opts,
-          DEPOT_DEPS_NAME[current_depot]['custom_deps'], cwd=config_path):
-        return []
-      if bisect_utils.RunGClient(
-          ['sync', '--revision', previous_revision], cwd=self.src_cwd):
-        return []
-
-    if current_depot == 'v8_bleeding_edge':
-      self.ChangeToDepotWorkingDirectory('chromium')
-
-      shutil.move('v8', 'v8.bak')
-      shutil.move('v8_bleeding_edge', 'v8')
-
-      self.cleanup_commands.append(['mv', 'v8', 'v8_bleeding_edge'])
-      self.cleanup_commands.append(['mv', 'v8.bak', 'v8'])
-
-      self.depot_cwd['v8_bleeding_edge'] = os.path.join(self.src_cwd, 'v8')
-      self.depot_cwd['v8'] = os.path.join(self.src_cwd, 'v8.bak')
-
-      self.ChangeToDepotWorkingDirectory(current_depot)
-
-    depot_revision_list = self.GetRevisionList(current_depot,
-                                               end_revision,
-                                               start_revision)
-
-    self.ChangeToDepotWorkingDirectory('chromium')
-
-    return depot_revision_list
-
-  def GatherReferenceValues(self, good_rev, bad_rev, cmd, metric, target_depot):
-    """Gathers reference values by running the performance tests on the
-    known good and bad revisions.
-
-    Args:
-      good_rev: The last known good revision where the performance regression
-        has not occurred yet.
-      bad_rev: A revision where the performance regression has already occurred.
-      cmd: The command to execute the performance test.
-      metric: The metric being tested for regression.
-
-    Returns:
-      A tuple with the results of building and running each revision.
-    """
-    bad_run_results = self.RunTest(bad_rev, target_depot, cmd, metric)
-
-    good_run_results = None
-
-    if not bad_run_results[1]:
-      good_run_results = self.RunTest(good_rev, target_depot, cmd, metric)
-
-    return (bad_run_results, good_run_results)
-
-  def PrintRevisionsToBisectMessage(self, revision_list, depot):
-    if self.opts.output_buildbot_annotations:
-      step_name = 'Bisection Range: [%s - %s]' % (
-          revision_list[len(revision_list)-1], revision_list[0])
-      bisect_utils.OutputAnnotationStepStart(step_name)
-
-    print
-    print 'Revisions to bisect on [%s]:' % depot
-    for revision_id in revision_list:
-      print '  -> %s' % (revision_id, )
-    print
-
-    if self.opts.output_buildbot_annotations:
-      bisect_utils.OutputAnnotationStepClosed()
-
-  def NudgeRevisionsIfDEPSChange(self, bad_revision, good_revision,
-                                 good_svn_revision=None):
-    """Checks to see if changes to DEPS file occurred, and that the revision
-    range also includes the change to .DEPS.git. If it doesn't, attempts to
-    expand the revision range to include it.
-
-    Args:
-      bad_revision: First known bad git revision.
-      good_revision: Last known good git revision.
-      good_svn_revision: Last known good svn revision.
-
-    Returns:
-      A tuple with the new bad and good revisions.
-    """
-    # DONOT perform nudge because at revision 291563 .DEPS.git was removed
-    # and source contain only DEPS file for dependency changes.
-    if good_svn_revision >= 291563:
-      return (bad_revision, good_revision)
-
-    if self.source_control.IsGit() and self.opts.target_platform == 'chromium':
-      changes_to_deps = self.source_control.QueryFileRevisionHistory(
-          bisect_utils.FILE_DEPS, good_revision, bad_revision)
-
-      if changes_to_deps:
-        # DEPS file was changed, search from the oldest change to DEPS file to
-        # bad_revision to see if there are matching .DEPS.git changes.
-        oldest_deps_change = changes_to_deps[-1]
-        changes_to_gitdeps = self.source_control.QueryFileRevisionHistory(
-            bisect_utils.FILE_DEPS_GIT, oldest_deps_change, bad_revision)
-
-        if len(changes_to_deps) != len(changes_to_gitdeps):
-          # Grab the timestamp of the last DEPS change
-          cmd = ['log', '--format=%ct', '-1', changes_to_deps[0]]
-          output = bisect_utils.CheckRunGit(cmd)
-          commit_time = int(output)
-
-          # Try looking for a commit that touches the .DEPS.git file in the
-          # next 15 minutes after the DEPS file change.
-          cmd = ['log', '--format=%H', '-1',
-              '--before=%d' % (commit_time + 900), '--after=%d' % commit_time,
-              'origin/master', '--', bisect_utils.FILE_DEPS_GIT]
-          output = bisect_utils.CheckRunGit(cmd)
-          output = output.strip()
-          if output:
-            self.warnings.append('Detected change to DEPS and modified '
-                'revision range to include change to .DEPS.git')
-            return (output, good_revision)
-          else:
-            self.warnings.append('Detected change to DEPS but couldn\'t find '
-                'matching change to .DEPS.git')
-    return (bad_revision, good_revision)
-
-  def CheckIfRevisionsInProperOrder(
-      self, target_depot, good_revision, bad_revision):
-    """Checks that |good_revision| is an earlier revision than |bad_revision|.
-
-    Args:
-      good_revision: Number/tag of the known good revision.
-      bad_revision: Number/tag of the known bad revision.
-
-    Returns:
-      True if the revisions are in the proper order (good earlier than bad).
-    """
-    if self.source_control.IsGit() and target_depot != 'cros':
-      cwd = self._GetDepotDirectory(target_depot)
-
-      cmd = ['log', '--format=%ct', '-1', good_revision]
-      output = bisect_utils.CheckRunGit(cmd, cwd=cwd)
-      good_commit_time = int(output)
-
-      cmd = ['log', '--format=%ct', '-1', bad_revision]
-      output = bisect_utils.CheckRunGit(cmd, cwd=cwd)
-      bad_commit_time = int(output)
-
-      return good_commit_time <= bad_commit_time
-    else:
-      # CrOS and SVN use integers.
-      return int(good_revision) <= int(bad_revision)
-
-  def CanPerformBisect(self, good_revision, bad_revision):
-    """Checks whether a given revision is bisectable.
-
-    Checks for following:
-    1. Non-bisectable revsions for android bots (refer to crbug.com/385324).
-    2. Non-bisectable revsions for Windows bots (refer to crbug.com/405274).
-
-    Args:
-      good_revision: Known good revision.
-      bad_revision: Known bad revision.
-
-    Returns:
-      A dictionary indicating the result. If revision is not bisectable,
-      this will contain the field "error", otherwise None.
-    """
-    if self.opts.target_platform == 'android':
-      revision_to_check = self.source_control.GetCommitPosition(good_revision)
-      if (bisect_utils.IsStringInt(good_revision)
-          and good_revision < 265549):
-        return {'error': (
-            'Bisect cannot continue for the given revision range.\n'
-            'It is impossible to bisect Android regressions '
-            'prior to r265549, which allows the bisect bot to '
-            'rely on Telemetry to do apk installation of the most recently '
-            'built local ChromeShell(refer to crbug.com/385324).\n'
-            'Please try bisecting revisions greater than or equal to r265549.')}
-
-    if bisect_utils.IsWindowsHost():
-      good_revision = self.source_control.GetCommitPosition(good_revision)
-      bad_revision = self.source_control.GetCommitPosition(bad_revision)
-      if (bisect_utils.IsStringInt(good_revision) and
-          bisect_utils.IsStringInt(bad_revision)):
-        if (289987 <= good_revision < 290716 or
-            289987 <= bad_revision < 290716):
-          return {'error': ('Oops! Revision between r289987 and r290716 are '
-                            'marked as dead zone for Windows due to '
-                            'crbug.com/405274. Please try another range.')}
-
-    return None
-
-  def Run(self, command_to_run, bad_revision_in, good_revision_in, metric):
-    """Given known good and bad revisions, run a binary search on all
-    intermediate revisions to determine the CL where the performance regression
-    occurred.
-
-    Args:
-      command_to_run: Specify the command to execute the performance test.
-      good_revision: Number/tag of the known good revision.
-      bad_revision: Number/tag of the known bad revision.
-      metric: The performance metric to monitor.
-
-    Returns:
-      A dict with 2 members, 'revision_data' and 'error'. On success,
-      'revision_data' will contain a dict mapping revision ids to
-      data about that revision. Each piece of revision data consists of a
-      dict with the following keys:
-
-      'passed': Represents whether the performance test was successful at
-          that revision. Possible values include: 1 (passed), 0 (failed),
-          '?' (skipped), 'F' (build failed).
-      'depot': The depot that this revision is from (i.e. WebKit)
-      'external': If the revision is a 'src' revision, 'external' contains
-          the revisions of each of the external libraries.
-      'sort': A sort value for sorting the dict in order of commits.
-
-      For example:
-      {
-        'error':None,
-        'revision_data':
-        {
-          'CL #1':
-          {
-            'passed': False,
-            'depot': 'chromium',
-            'external': None,
-            'sort': 0
-          }
-        }
-      }
-
-      If an error occurred, the 'error' field will contain the message and
-      'revision_data' will be empty.
-    """
-    results = {
-        'revision_data' : {},
-        'error' : None,
-    }
-
-    # Choose depot to bisect first
-    target_depot = 'chromium'
-    if self.opts.target_platform == 'cros':
-      target_depot = 'cros'
-    elif self.opts.target_platform == 'android-chrome':
-      target_depot = 'android-chrome'
-
-    cwd = os.getcwd()
-    self.ChangeToDepotWorkingDirectory(target_depot)
-
-    # If they passed SVN revisions, we can try match them to git SHA1 hashes.
-    bad_revision = self.source_control.ResolveToRevision(
-        bad_revision_in, target_depot, DEPOT_DEPS_NAME, 100)
-    good_revision = self.source_control.ResolveToRevision(
-        good_revision_in, target_depot, DEPOT_DEPS_NAME, -100)
-
-    os.chdir(cwd)
-    if bad_revision is None:
-      results['error'] = 'Couldn\'t resolve [%s] to SHA1.' % bad_revision_in
-      return results
-
-    if good_revision is None:
-      results['error'] = 'Couldn\'t resolve [%s] to SHA1.' % good_revision_in
-      return results
-
-    # Check that they didn't accidentally swap good and bad revisions.
-    if not self.CheckIfRevisionsInProperOrder(
-        target_depot, good_revision, bad_revision):
-      results['error'] = ('bad_revision < good_revision, did you swap these '
-                          'by mistake?')
-      return results
-    bad_revision, good_revision = self.NudgeRevisionsIfDEPSChange(
-        bad_revision, good_revision, good_revision_in)
-    if self.opts.output_buildbot_annotations:
-      bisect_utils.OutputAnnotationStepStart('Gathering Revisions')
-
-    cannot_bisect = self.CanPerformBisect(good_revision, bad_revision)
-    if cannot_bisect:
-      results['error'] = cannot_bisect.get('error')
-      return results
-
-    print 'Gathering revision range for bisection.'
-    # Retrieve a list of revisions to do bisection on.
-    src_revision_list = self.GetRevisionList(
-        target_depot, bad_revision, good_revision)
-
-    if self.opts.output_buildbot_annotations:
-      bisect_utils.OutputAnnotationStepClosed()
-
-    if src_revision_list:
-      # revision_data will store information about a revision such as the
-      # depot it came from, the webkit/V8 revision at that time,
-      # performance timing, build state, etc...
-      revision_data = results['revision_data']
-
-      # revision_list is the list we're binary searching through at the moment.
-      revision_list = []
-
-      sort_key_ids = 0
-
-      for current_revision_id in src_revision_list:
-        sort_key_ids += 1
-
-        revision_data[current_revision_id] = {
-            'value' : None,
-            'passed' : '?',
-            'depot' : target_depot,
-            'external' : None,
-            'perf_time' : 0,
-            'build_time' : 0,
-            'sort' : sort_key_ids,
-        }
-        revision_list.append(current_revision_id)
-
-      min_revision = 0
-      max_revision = len(revision_list) - 1
-
-      self.PrintRevisionsToBisectMessage(revision_list, target_depot)
-
-      if self.opts.output_buildbot_annotations:
-        bisect_utils.OutputAnnotationStepStart('Gathering Reference Values')
-
-      print 'Gathering reference values for bisection.'
-
-      # Perform the performance tests on the good and bad revisions, to get
-      # reference values.
-      bad_results, good_results = self.GatherReferenceValues(good_revision,
-                                                               bad_revision,
-                                                               command_to_run,
-                                                               metric,
-                                                               target_depot)
-
-      if self.opts.output_buildbot_annotations:
-        bisect_utils.OutputAnnotationStepClosed()
-
-      if bad_results[1]:
-        results['error'] = ('An error occurred while building and running '
-            'the \'bad\' reference value. The bisect cannot continue without '
-            'a working \'bad\' revision to start from.\n\nError: %s' %
-                bad_results[0])
-        return results
-
-      if good_results[1]:
-        results['error'] = ('An error occurred while building and running '
-            'the \'good\' reference value. The bisect cannot continue without '
-            'a working \'good\' revision to start from.\n\nError: %s' %
-                good_results[0])
-        return results
-
-
-      # We need these reference values to determine if later runs should be
-      # classified as pass or fail.
-      known_bad_value = bad_results[0]
-      known_good_value = good_results[0]
-
-      # Can just mark the good and bad revisions explicitly here since we
-      # already know the results.
-      bad_revision_data = revision_data[revision_list[0]]
-      bad_revision_data['external'] = bad_results[2]
-      bad_revision_data['perf_time'] = bad_results[3]
-      bad_revision_data['build_time'] = bad_results[4]
-      bad_revision_data['passed'] = False
-      bad_revision_data['value'] = known_bad_value
-
-      good_revision_data = revision_data[revision_list[max_revision]]
-      good_revision_data['external'] = good_results[2]
-      good_revision_data['perf_time'] = good_results[3]
-      good_revision_data['build_time'] = good_results[4]
-      good_revision_data['passed'] = True
-      good_revision_data['value'] = known_good_value
-
-      next_revision_depot = target_depot
-
-      while True:
-        if not revision_list:
-          break
-
-        min_revision_data = revision_data[revision_list[min_revision]]
-        max_revision_data = revision_data[revision_list[max_revision]]
-
-        if max_revision - min_revision <= 1:
-          current_depot = min_revision_data['depot']
-          if min_revision_data['passed'] == '?':
-            next_revision_index = min_revision
-          elif max_revision_data['passed'] == '?':
-            next_revision_index = max_revision
-          elif current_depot in ['android-chrome', 'cros', 'chromium', 'v8']:
-            previous_revision = revision_list[min_revision]
-            # If there were changes to any of the external libraries we track,
-            # should bisect the changes there as well.
-            external_depot = self._FindNextDepotToBisect(
-                current_depot, min_revision_data, max_revision_data)
-            # If there was no change in any of the external depots, the search
-            # is over.
-            if not external_depot:
-              if current_depot == 'v8':
-                self.warnings.append('Unfortunately, V8 bisection couldn\'t '
-                    'continue any further. The script can only bisect into '
-                    'V8\'s bleeding_edge repository if both the current and '
-                    'previous revisions in trunk map directly to revisions in '
-                    'bleeding_edge.')
-              break
-
-            earliest_revision = max_revision_data['external'][external_depot]
-            latest_revision = min_revision_data['external'][external_depot]
-
-            new_revision_list = self.PrepareToBisectOnDepot(
-                external_depot, latest_revision, earliest_revision,
-                previous_revision)
-
-            if not new_revision_list:
-              results['error'] = ('An error occurred attempting to retrieve '
-                                  'revision range: [%s..%s]' %
-                                  (earliest_revision, latest_revision))
-              return results
-
-            _AddRevisionsIntoRevisionData(
-                new_revision_list, external_depot, min_revision_data['sort'],
-                revision_data)
-
-            # Reset the bisection and perform it on the newly inserted
-            # changelists.
-            revision_list = new_revision_list
-            min_revision = 0
-            max_revision = len(revision_list) - 1
-            sort_key_ids += len(revision_list)
-
-            print ('Regression in metric %s appears to be the result of '
-                   'changes in [%s].' % (metric, external_depot))
-
-            self.PrintRevisionsToBisectMessage(revision_list, external_depot)
-
-            continue
-          else:
-            break
-        else:
-          next_revision_index = (int((max_revision - min_revision) / 2) +
-                                 min_revision)
-
-        next_revision_id = revision_list[next_revision_index]
-        next_revision_data = revision_data[next_revision_id]
-        next_revision_depot = next_revision_data['depot']
-
-        self.ChangeToDepotWorkingDirectory(next_revision_depot)
-
-        if self.opts.output_buildbot_annotations:
-          step_name = 'Working on [%s]' % next_revision_id
-          bisect_utils.OutputAnnotationStepStart(step_name)
-
-        print 'Working on revision: [%s]' % next_revision_id
-
-        run_results = self.RunTest(
-            next_revision_id, next_revision_depot, command_to_run, metric,
-            skippable=True)
-
-        # If the build is successful, check whether or not the metric
-        # had regressed.
-        if not run_results[1]:
-          if len(run_results) > 2:
-            next_revision_data['external'] = run_results[2]
-            next_revision_data['perf_time'] = run_results[3]
-            next_revision_data['build_time'] = run_results[4]
-
-          passed_regression = self._CheckIfRunPassed(run_results[0],
-                                                     known_good_value,
-                                                     known_bad_value)
-
-          next_revision_data['passed'] = passed_regression
-          next_revision_data['value'] = run_results[0]
-
-          if passed_regression:
-            max_revision = next_revision_index
-          else:
-            min_revision = next_revision_index
-        else:
-          if run_results[1] == BUILD_RESULT_SKIPPED:
-            next_revision_data['passed'] = 'Skipped'
-          elif run_results[1] == BUILD_RESULT_FAIL:
-            next_revision_data['passed'] = 'Build Failed'
-
-          print run_results[0]
-
-          # If the build is broken, remove it and redo search.
-          revision_list.pop(next_revision_index)
-
-          max_revision -= 1
-
-        if self.opts.output_buildbot_annotations:
-          self._PrintPartialResults(results)
-          bisect_utils.OutputAnnotationStepClosed()
-    else:
-      # Weren't able to sync and retrieve the revision range.
-      results['error'] = ('An error occurred attempting to retrieve revision '
-                          'range: [%s..%s]' % (good_revision, bad_revision))
-
-    return results
-
-  def _PrintPartialResults(self, results_dict):
-    revision_data = results_dict['revision_data']
-    revision_data_sorted = sorted(revision_data.iteritems(),
-                                  key = lambda x: x[1]['sort'])
-    results_dict = self._GetResultsDict(revision_data, revision_data_sorted)
-
-    self._PrintTestedCommitsTable(revision_data_sorted,
-                                  results_dict['first_working_revision'],
-                                  results_dict['last_broken_revision'],
-                                  100, final_step=False)
-
-  def _ConfidenceLevelStatus(self, results_dict):
-    if not results_dict['confidence']:
-      return None
-    confidence_status = 'Successful with %(level)s confidence%(warning)s.'
-    if results_dict['confidence'] >= HIGH_CONFIDENCE:
-      level = 'high'
-    else:
-      level = 'low'
-    warning = ' and warnings'
-    if not self.warnings:
-      warning = ''
-    return confidence_status % {'level': level, 'warning': warning}
-
-  def _GetViewVCLinkFromDepotAndHash(self, cl, depot):
-    info = self.source_control.QueryRevisionInfo(cl,
-        self._GetDepotDirectory(depot))
-    if depot and DEPOT_DEPS_NAME[depot].has_key('viewvc'):
-      try:
-        # Format is "git-svn-id: svn://....@123456 <other data>"
-        svn_line = [i for i in info['body'].splitlines() if 'git-svn-id:' in i]
-        svn_revision = svn_line[0].split('@')
-        svn_revision = svn_revision[1].split(' ')[0]
-        return DEPOT_DEPS_NAME[depot]['viewvc'] + svn_revision
-      except IndexError:
-        return ''
-    return ''
-
-  def _PrintRevisionInfo(self, cl, info, depot=None):
-    email_info = ''
-    if not info['email'].startswith(info['author']):
-      email_info = '\nEmail   : %s' % info['email']
-    commit_link = self._GetViewVCLinkFromDepotAndHash(cl, depot)
-    if commit_link:
-      commit_info = '\nLink    : %s' % commit_link
-    else:
-      commit_info = ('\nFailed to parse SVN revision from body:\n%s' %
-                     info['body'])
-    print RESULTS_REVISION_INFO % {
-        'subject': info['subject'],
-        'author': info['author'],
-        'email_info': email_info,
-        'commit_info': commit_info,
-        'cl': cl,
-        'cl_date': info['date']
-    }
-
-  def _PrintTestedCommitsHeader(self):
-    if self.opts.bisect_mode == BISECT_MODE_MEAN:
-      _PrintTableRow(
-          [20, 70, 14, 12, 13],
-          ['Depot', 'Commit SHA', 'Mean', 'Std. Error', 'State'])
-    elif self.opts.bisect_mode == BISECT_MODE_STD_DEV:
-      _PrintTableRow(
-          [20, 70, 14, 12, 13],
-          ['Depot', 'Commit SHA', 'Std. Error', 'Mean', 'State'])
-    elif self.opts.bisect_mode == BISECT_MODE_RETURN_CODE:
-      _PrintTableRow(
-          [20, 70, 14, 13],
-          ['Depot', 'Commit SHA', 'Return Code', 'State'])
-    else:
-      assert False, 'Invalid bisect_mode specified.'
-
-  def _PrintTestedCommitsEntry(self, current_data, cl_link, state_str):
-    if self.opts.bisect_mode == BISECT_MODE_MEAN:
-      std_error = '+-%.02f' % current_data['value']['std_err']
-      mean = '%.02f' % current_data['value']['mean']
-      _PrintTableRow(
-          [20, 70, 12, 14, 13],
-          [current_data['depot'], cl_link, mean, std_error, state_str])
-    elif self.opts.bisect_mode == BISECT_MODE_STD_DEV:
-      std_error = '+-%.02f' % current_data['value']['std_err']
-      mean = '%.02f' % current_data['value']['mean']
-      _PrintTableRow(
-          [20, 70, 12, 14, 13],
-          [current_data['depot'], cl_link, std_error, mean, state_str])
-    elif self.opts.bisect_mode == BISECT_MODE_RETURN_CODE:
-      mean = '%d' % current_data['value']['mean']
-      _PrintTableRow(
-          [20, 70, 14, 13],
-          [current_data['depot'], cl_link, mean, state_str])
-
-  def _PrintTestedCommitsTable(
-      self, revision_data_sorted, first_working_revision, last_broken_revision,
-      confidence, final_step=True):
-    print
-    if final_step:
-      print '===== TESTED COMMITS ====='
-    else:
-      print '===== PARTIAL RESULTS ====='
-    self._PrintTestedCommitsHeader()
-    state = 0
-    for current_id, current_data in revision_data_sorted:
-      if current_data['value']:
-        if (current_id == last_broken_revision or
-            current_id == first_working_revision):
-          # If confidence is too low, don't add this empty line since it's
-          # used to put focus on a suspected CL.
-          if confidence and final_step:
-            print
-          state += 1
-          if state == 2 and not final_step:
-            # Just want a separation between "bad" and "good" cl's.
-            print
-
-        state_str = 'Bad'
-        if state == 1 and final_step:
-          state_str = 'Suspected CL'
-        elif state == 2:
-          state_str = 'Good'
-
-        # If confidence is too low, don't bother outputting good/bad.
-        if not confidence:
-          state_str = ''
-        state_str = state_str.center(13, ' ')
-
-        cl_link = self._GetViewVCLinkFromDepotAndHash(current_id,
-            current_data['depot'])
-        if not cl_link:
-          cl_link = current_id
-        self._PrintTestedCommitsEntry(current_data, cl_link, state_str)
-
-  def _PrintReproSteps(self):
-    """Prints out a section of the results explaining how to run the test.
-
-    This message includes the command used to run the test.
-    """
-    command = '$ ' + self.opts.command
-    if bisect_utils.IsTelemetryCommand(self.opts.command):
-      command += ('\nAlso consider passing --profiler=list to see available '
-                  'profilers.')
-    print REPRO_STEPS_LOCAL
-    if bisect_utils.IsTelemetryCommand(self.opts.command):
-      telemetry_command = re.sub(r'--browser=[^\s]+',
-                                 '--browser=<bot-name>',
-                                 command)
-      print REPRO_STEPS_TRYJOB_TELEMETRY % {'command': telemetry_command}
-    else:
-      print REPRO_STEPS_TRYJOB
-
-  def _PrintOtherRegressions(self, other_regressions, revision_data):
-    """Prints a section of the results about other potential regressions."""
-    print
-    print 'Other regressions may have occurred:'
-    print '  %8s  %70s  %10s' % ('Depot'.center(8, ' '),
-        'Range'.center(70, ' '), 'Confidence'.center(10, ' '))
-    for regression in other_regressions:
-      current_id, previous_id, confidence = regression
-      current_data = revision_data[current_id]
-      previous_data = revision_data[previous_id]
-
-      current_link = self._GetViewVCLinkFromDepotAndHash(current_id,
-          current_data['depot'])
-      previous_link = self._GetViewVCLinkFromDepotAndHash(previous_id,
-          previous_data['depot'])
-
-      # If we can't map it to a viewable URL, at least show the original hash.
-      if not current_link:
-        current_link = current_id
-      if not previous_link:
-        previous_link = previous_id
-
-      print '  %8s  %70s %s' % (
-          current_data['depot'], current_link,
-          ('%d%%' % confidence).center(10, ' '))
-      print '  %8s  %70s' % (
-          previous_data['depot'], previous_link)
-      print
-
-  def _GetResultsDict(self, revision_data, revision_data_sorted):
-    # Find range where it possibly broke.
-    first_working_revision = None
-    first_working_revision_index = -1
-    last_broken_revision = None
-    last_broken_revision_index = -1
-
-    culprit_revisions = []
-    other_regressions = []
-    regression_size = 0.0
-    regression_std_err = 0.0
-    confidence = 0.0
-
-    for i in xrange(len(revision_data_sorted)):
-      k, v = revision_data_sorted[i]
-      if v['passed'] == 1:
-        if not first_working_revision:
-          first_working_revision = k
-          first_working_revision_index = i
-
-      if not v['passed']:
-        last_broken_revision = k
-        last_broken_revision_index = i
-
-    if last_broken_revision != None and first_working_revision != None:
-      broken_means = []
-      for i in xrange(0, last_broken_revision_index + 1):
-        if revision_data_sorted[i][1]['value']:
-          broken_means.append(revision_data_sorted[i][1]['value']['values'])
-
-      working_means = []
-      for i in xrange(first_working_revision_index, len(revision_data_sorted)):
-        if revision_data_sorted[i][1]['value']:
-          working_means.append(revision_data_sorted[i][1]['value']['values'])
-
-      # Flatten the lists to calculate mean of all values.
-      working_mean = sum(working_means, [])
-      broken_mean = sum(broken_means, [])
-
-      # Calculate the approximate size of the regression
-      mean_of_bad_runs = math_utils.Mean(broken_mean)
-      mean_of_good_runs = math_utils.Mean(working_mean)
-
-      regression_size = 100 * math_utils.RelativeChange(mean_of_good_runs,
-                                                      mean_of_bad_runs)
-      if math.isnan(regression_size):
-        regression_size = 'zero-to-nonzero'
-
-      regression_std_err = math.fabs(math_utils.PooledStandardError(
-          [working_mean, broken_mean]) /
-          max(0.0001, min(mean_of_good_runs, mean_of_bad_runs))) * 100.0
-
-      # Give a "confidence" in the bisect. At the moment we use how distinct the
-      # values are before and after the last broken revision, and how noisy the
-      # overall graph is.
-      confidence = ConfidenceScore(working_means, broken_means)
-
-      culprit_revisions = []
-
-      cwd = os.getcwd()
-      self.ChangeToDepotWorkingDirectory(
-          revision_data[last_broken_revision]['depot'])
-
-      if revision_data[last_broken_revision]['depot'] == 'cros':
-        # Want to get a list of all the commits and what depots they belong
-        # to so that we can grab info about each.
-        cmd = ['repo', 'forall', '-c',
-            'pwd ; git log --pretty=oneline --before=%d --after=%d' % (
-            last_broken_revision, first_working_revision + 1)]
-        output, return_code = bisect_utils.RunProcessAndRetrieveOutput(cmd)
-
-        changes = []
-        assert not return_code, ('An error occurred while running '
-                                 '"%s"' % ' '.join(cmd))
-        last_depot = None
-        cwd = os.getcwd()
-        for l in output.split('\n'):
-          if l:
-            # Output will be in form:
-            # /path_to_depot
-            # /path_to_other_depot
-            # <SHA1>
-            # /path_again
-            # <SHA1>
-            # etc.
-            if l[0] == '/':
-              last_depot = l
-            else:
-              contents = l.split(' ')
-              if len(contents) > 1:
-                changes.append([last_depot, contents[0]])
-        for c in changes:
-          os.chdir(c[0])
-          info = self.source_control.QueryRevisionInfo(c[1])
-          culprit_revisions.append((c[1], info, None))
-      else:
-        for i in xrange(last_broken_revision_index, len(revision_data_sorted)):
-          k, v = revision_data_sorted[i]
-          if k == first_working_revision:
-            break
-          self.ChangeToDepotWorkingDirectory(v['depot'])
-          info = self.source_control.QueryRevisionInfo(k)
-          culprit_revisions.append((k, info, v['depot']))
-      os.chdir(cwd)
-
-      # Check for any other possible regression ranges.
-      other_regressions = _FindOtherRegressions(
-          revision_data_sorted, mean_of_bad_runs > mean_of_good_runs)
-
-    return {
-        'first_working_revision': first_working_revision,
-        'last_broken_revision': last_broken_revision,
-        'culprit_revisions': culprit_revisions,
-        'other_regressions': other_regressions,
-        'regression_size': regression_size,
-        'regression_std_err': regression_std_err,
-        'confidence': confidence,
-    }
-
-  def _CheckForWarnings(self, results_dict):
-    if len(results_dict['culprit_revisions']) > 1:
-      self.warnings.append('Due to build errors, regression range could '
-                           'not be narrowed down to a single commit.')
-    if self.opts.repeat_test_count == 1:
-      self.warnings.append('Tests were only set to run once. This may '
-                           'be insufficient to get meaningful results.')
-    if 0 < results_dict['confidence'] < HIGH_CONFIDENCE:
-      self.warnings.append('Confidence is not high. Try bisecting again '
-                           'with increased repeat_count, larger range, or '
-                           'on another metric.')
-    if not results_dict['confidence']:
-      self.warnings.append('Confidence score is 0%. Try bisecting again on '
-                           'another platform or another metric.')
-
-  def FormatAndPrintResults(self, bisect_results):
-    """Prints the results from a bisection run in a readable format.
-
-    Args:
-      bisect_results: The results from a bisection test run.
-    """
-    revision_data = bisect_results['revision_data']
-    revision_data_sorted = sorted(revision_data.iteritems(),
-                                  key = lambda x: x[1]['sort'])
-    results_dict = self._GetResultsDict(revision_data, revision_data_sorted)
-
-    self._CheckForWarnings(results_dict)
-
-    if self.opts.output_buildbot_annotations:
-      bisect_utils.OutputAnnotationStepStart('Build Status Per Revision')
-
-    print
-    print 'Full results of bisection:'
-    for current_id, current_data  in revision_data_sorted:
-      build_status = current_data['passed']
-
-      if type(build_status) is bool:
-        if build_status:
-          build_status = 'Good'
-        else:
-          build_status = 'Bad'
-
-      print '  %20s  %40s  %s' % (current_data['depot'],
-                                  current_id, build_status)
-    print
-
-    if self.opts.output_buildbot_annotations:
-      bisect_utils.OutputAnnotationStepClosed()
-      # The perf dashboard scrapes the "results" step in order to comment on
-      # bugs. If you change this, please update the perf dashboard as well.
-      bisect_utils.OutputAnnotationStepStart('Results')
-
-    self._PrintBanner(results_dict)
-    self._PrintWarnings()
-
-    if results_dict['culprit_revisions'] and results_dict['confidence']:
-      for culprit in results_dict['culprit_revisions']:
-        cl, info, depot = culprit
-        self._PrintRevisionInfo(cl, info, depot)
-      if results_dict['other_regressions']:
-        self._PrintOtherRegressions(results_dict['other_regressions'],
-                                    revision_data)
-    self._PrintTestedCommitsTable(revision_data_sorted,
-                                  results_dict['first_working_revision'],
-                                  results_dict['last_broken_revision'],
-                                  results_dict['confidence'])
-    _PrintStepTime(revision_data_sorted)
-    self._PrintReproSteps()
-    _PrintThankYou()
-    if self.opts.output_buildbot_annotations:
-      bisect_utils.OutputAnnotationStepClosed()
-
-  def _PrintBanner(self, results_dict):
-    if self._IsBisectModeReturnCode():
-      metrics = 'N/A'
-      change = 'Yes'
-    else:
-      metrics = '/'.join(self.opts.metric)
-      change = '%.02f%% (+/-%.02f%%)' % (
-          results_dict['regression_size'], results_dict['regression_std_err'])
-
-    if results_dict['culprit_revisions'] and results_dict['confidence']:
-      status = self._ConfidenceLevelStatus(results_dict)
-    else:
-      status = 'Failure, could not reproduce.'
-      change = 'Bisect could not reproduce a change.'
-
-    print RESULTS_BANNER % {
-        'status': status,
-        'command': self.opts.command,
-        'metrics': metrics,
-        'change': change,
-        'confidence': results_dict['confidence'],
-    }
-
-  def _PrintWarnings(self):
-    """Prints a list of warning strings if there are any."""
-    if not self.warnings:
-      return
-    print
-    print 'WARNINGS:'
-    for w in set(self.warnings):
-      print '  ! %s' % w
-
-
-def _IsPlatformSupported():
-  """Checks that this platform and build system are supported.
-
-  Args:
-    opts: The options parsed from the command line.
-
-  Returns:
-    True if the platform and build system are supported.
-  """
-  # Haven't tested the script out on any other platforms yet.
-  supported = ['posix', 'nt']
-  return os.name in supported
-
-
-def RmTreeAndMkDir(path_to_dir, skip_makedir=False):
-  """Removes the directory tree specified, and then creates an empty
-  directory in the same location (if not specified to skip).
-
-  Args:
-    path_to_dir: Path to the directory tree.
-    skip_makedir: Whether to skip creating empty directory, default is False.
-
-  Returns:
-    True if successful, False if an error occurred.
-  """
-  try:
-    if os.path.exists(path_to_dir):
-      shutil.rmtree(path_to_dir)
-  except OSError, e:
-    if e.errno != errno.ENOENT:
-      return False
-
-  if not skip_makedir:
-    return MaybeMakeDirectory(path_to_dir)
-
-  return True
-
-
-def RemoveBuildFiles(build_type):
-  """Removes build files from previous runs."""
-  if RmTreeAndMkDir(os.path.join('out', build_type)):
-    if RmTreeAndMkDir(os.path.join('build', build_type)):
-      return True
-  return False
-
-
-class BisectOptions(object):
-  """Options to be used when running bisection."""
-  def __init__(self):
-    super(BisectOptions, self).__init__()
-
-    self.target_platform = 'chromium'
-    self.build_preference = None
-    self.good_revision = None
-    self.bad_revision = None
-    self.use_goma = None
-    self.goma_dir = None
-    self.cros_board = None
-    self.cros_remote_ip = None
-    self.repeat_test_count = 20
-    self.truncate_percent = 25
-    self.max_time_minutes = 20
-    self.metric = None
-    self.command = None
-    self.output_buildbot_annotations = None
-    self.no_custom_deps = False
-    self.working_directory = None
-    self.extra_src = None
-    self.debug_ignore_build = None
-    self.debug_ignore_sync = None
-    self.debug_ignore_perf_test = None
-    self.gs_bucket = None
-    self.target_arch = 'ia32'
-    self.target_build_type = 'Release'
-    self.builder_host = None
-    self.builder_port = None
-    self.bisect_mode = BISECT_MODE_MEAN
-
-  @staticmethod
-  def _CreateCommandLineParser():
-    """Creates a parser with bisect options.
-
-    Returns:
-      An instance of optparse.OptionParser.
-    """
-    usage = ('%prog [options] [-- chromium-options]\n'
-             'Perform binary search on revision history to find a minimal '
-             'range of revisions where a performance metric regressed.\n')
-
-    parser = optparse.OptionParser(usage=usage)
-
-    group = optparse.OptionGroup(parser, 'Bisect options')
-    group.add_option('-c', '--command',
-                     type='str',
-                     help='A command to execute your performance test at' +
-                     ' each point in the bisection.')
-    group.add_option('-b', '--bad_revision',
-                     type='str',
-                     help='A bad revision to start bisection. ' +
-                     'Must be later than good revision. May be either a git' +
-                     ' or svn revision.')
-    group.add_option('-g', '--good_revision',
-                     type='str',
-                     help='A revision to start bisection where performance' +
-                     ' test is known to pass. Must be earlier than the ' +
-                     'bad revision. May be either a git or svn revision.')
-    group.add_option('-m', '--metric',
-                     type='str',
-                     help='The desired metric to bisect on. For example ' +
-                     '"vm_rss_final_b/vm_rss_f_b"')
-    group.add_option('-r', '--repeat_test_count',
-                     type='int',
-                     default=20,
-                     help='The number of times to repeat the performance '
-                     'test. Values will be clamped to range [1, 100]. '
-                     'Default value is 20.')
-    group.add_option('--max_time_minutes',
-                     type='int',
-                     default=20,
-                     help='The maximum time (in minutes) to take running the '
-                     'performance tests. The script will run the performance '
-                     'tests according to --repeat_test_count, so long as it '
-                     'doesn\'t exceed --max_time_minutes. Values will be '
-                     'clamped to range [1, 60].'
-                     'Default value is 20.')
-    group.add_option('-t', '--truncate_percent',
-                     type='int',
-                     default=25,
-                     help='The highest/lowest % are discarded to form a '
-                     'truncated mean. Values will be clamped to range [0, '
-                     '25]. Default value is 25 (highest/lowest 25% will be '
-                     'discarded).')
-    group.add_option('--bisect_mode',
-                     type='choice',
-                     choices=[BISECT_MODE_MEAN, BISECT_MODE_STD_DEV,
-                        BISECT_MODE_RETURN_CODE],
-                     default=BISECT_MODE_MEAN,
-                     help='The bisect mode. Choices are to bisect on the '
-                     'difference in mean, std_dev, or return_code.')
-    parser.add_option_group(group)
-
-    group = optparse.OptionGroup(parser, 'Build options')
-    group.add_option('-w', '--working_directory',
-                     type='str',
-                     help='Path to the working directory where the script '
-                     'will do an initial checkout of the chromium depot. The '
-                     'files will be placed in a subdirectory "bisect" under '
-                     'working_directory and that will be used to perform the '
-                     'bisection. This parameter is optional, if it is not '
-                     'supplied, the script will work from the current depot.')
-    group.add_option('--build_preference',
-                     type='choice',
-                     choices=['msvs', 'ninja', 'make'],
-                     help='The preferred build system to use. On linux/mac '
-                     'the options are make/ninja. On Windows, the options '
-                     'are msvs/ninja.')
-    group.add_option('--target_platform',
-                     type='choice',
-                     choices=['chromium', 'cros', 'android', 'android-chrome'],
-                     default='chromium',
-                     help='The target platform. Choices are "chromium" '
-                     '(current platform), "cros", or "android". If you '
-                     'specify something other than "chromium", you must be '
-                     'properly set up to build that platform.')
-    group.add_option('--no_custom_deps',
-                     dest='no_custom_deps',
-                     action='store_true',
-                     default=False,
-                     help='Run the script with custom_deps or not.')
-    group.add_option('--extra_src',
-                     type='str',
-                     help='Path to a script which can be used to modify '
-                     'the bisect script\'s behavior.')
-    group.add_option('--cros_board',
-                     type='str',
-                     help='The cros board type to build.')
-    group.add_option('--cros_remote_ip',
-                     type='str',
-                     help='The remote machine to image to.')
-    group.add_option('--use_goma',
-                     action='store_true',
-                     help='Add a bunch of extra threads for goma, and enable '
-                     'goma')
-    group.add_option('--goma_dir',
-                     help='Path to goma tools (or system default if not '
-                     'specified).')
-    group.add_option('--output_buildbot_annotations',
-                     action='store_true',
-                     help='Add extra annotation output for buildbot.')
-    group.add_option('--gs_bucket',
-                     default='',
-                     dest='gs_bucket',
-                     type='str',
-                     help=('Name of Google Storage bucket to upload or '
-                     'download build. e.g., chrome-perf'))
-    group.add_option('--target_arch',
-                     type='choice',
-                     choices=['ia32', 'x64', 'arm'],
-                     default='ia32',
-                     dest='target_arch',
-                     help=('The target build architecture. Choices are "ia32" '
-                     '(default), "x64" or "arm".'))
-    group.add_option('--target_build_type',
-                     type='choice',
-                     choices=['Release', 'Debug'],
-                     default='Release',
-                     help='The target build type. Choices are "Release" '
-                     '(default), or "Debug".')
-    group.add_option('--builder_host',
-                     dest='builder_host',
-                     type='str',
-                     help=('Host address of server to produce build by posting'
-                           ' try job request.'))
-    group.add_option('--builder_port',
-                     dest='builder_port',
-                     type='int',
-                     help=('HTTP port of the server to produce build by posting'
-                           ' try job request.'))
-    parser.add_option_group(group)
-
-    group = optparse.OptionGroup(parser, 'Debug options')
-    group.add_option('--debug_ignore_build',
-                     action='store_true',
-                     help='DEBUG: Don\'t perform builds.')
-    group.add_option('--debug_ignore_sync',
-                     action='store_true',
-                     help='DEBUG: Don\'t perform syncs.')
-    group.add_option('--debug_ignore_perf_test',
-                     action='store_true',
-                     help='DEBUG: Don\'t perform performance tests.')
-    parser.add_option_group(group)
-    return parser
-
-  def ParseCommandLine(self):
-    """Parses the command line for bisect options."""
-    parser = self._CreateCommandLineParser()
-    opts, _ = parser.parse_args()
-
-    try:
-      if not opts.command:
-        raise RuntimeError('missing required parameter: --command')
-
-      if not opts.good_revision:
-        raise RuntimeError('missing required parameter: --good_revision')
-
-      if not opts.bad_revision:
-        raise RuntimeError('missing required parameter: --bad_revision')
-
-      if not opts.metric and opts.bisect_mode != BISECT_MODE_RETURN_CODE:
-        raise RuntimeError('missing required parameter: --metric')
-
-      if opts.gs_bucket:
-        if not cloud_storage.List(opts.gs_bucket):
-          raise RuntimeError('Invalid Google Storage: gs://%s' % opts.gs_bucket)
-        if not opts.builder_host:
-          raise RuntimeError('Must specify try server host name using '
-                             '--builder_host when gs_bucket is used.')
-        if not opts.builder_port:
-          raise RuntimeError('Must specify try server port number using '
-                             '--builder_port when gs_bucket is used.')
-      if opts.target_platform == 'cros':
-        # Run sudo up front to make sure credentials are cached for later.
-        print 'Sudo is required to build cros:'
-        print
-        bisect_utils.RunProcess(['sudo', 'true'])
-
-        if not opts.cros_board:
-          raise RuntimeError('missing required parameter: --cros_board')
-
-        if not opts.cros_remote_ip:
-          raise RuntimeError('missing required parameter: --cros_remote_ip')
-
-        if not opts.working_directory:
-          raise RuntimeError('missing required parameter: --working_directory')
-
-      if opts.bisect_mode != BISECT_MODE_RETURN_CODE:
-        metric_values = opts.metric.split('/')
-        if len(metric_values) != 2:
-          raise RuntimeError('Invalid metric specified: [%s]' % opts.metric)
-        opts.metric = metric_values
-
-      opts.repeat_test_count = min(max(opts.repeat_test_count, 1), 100)
-      opts.max_time_minutes = min(max(opts.max_time_minutes, 1), 60)
-      opts.truncate_percent = min(max(opts.truncate_percent, 0), 25)
-      opts.truncate_percent = opts.truncate_percent / 100.0
-
-      for k, v in opts.__dict__.iteritems():
-        assert hasattr(self, k), 'Invalid %s attribute in BisectOptions.' % k
-        setattr(self, k, v)
-    except RuntimeError, e:
-      output_string = StringIO.StringIO()
-      parser.print_help(file=output_string)
-      error_message = '%s\n\n%s' % (e.message, output_string.getvalue())
-      output_string.close()
-      raise RuntimeError(error_message)
-
-  @staticmethod
-  def FromDict(values):
-    """Creates an instance of BisectOptions from a dictionary.
-
-    Args:
-      values: a dict containing options to set.
-
-    Returns:
-      An instance of BisectOptions.
-    """
-    opts = BisectOptions()
-    for k, v in values.iteritems():
-      assert hasattr(opts, k), 'Invalid %s attribute in BisectOptions.' % k
-      setattr(opts, k, v)
-
-    if opts.metric and opts.bisect_mode != BISECT_MODE_RETURN_CODE:
-      metric_values = opts.metric.split('/')
-      if len(metric_values) != 2:
-        raise RuntimeError('Invalid metric specified: [%s]' % opts.metric)
-      opts.metric = metric_values
-
-    opts.repeat_test_count = min(max(opts.repeat_test_count, 1), 100)
-    opts.max_time_minutes = min(max(opts.max_time_minutes, 1), 60)
-    opts.truncate_percent = min(max(opts.truncate_percent, 0), 25)
-    opts.truncate_percent = opts.truncate_percent / 100.0
-
-    return opts
-
-
-def main():
-
-  try:
-    opts = BisectOptions()
-    opts.ParseCommandLine()
-
-    if opts.extra_src:
-      extra_src = bisect_utils.LoadExtraSrc(opts.extra_src)
-      if not extra_src:
-        raise RuntimeError('Invalid or missing --extra_src.')
-      _AddAdditionalDepotInfo(extra_src.GetAdditionalDepotInfo())
-
-    if opts.working_directory:
-      custom_deps = bisect_utils.DEFAULT_GCLIENT_CUSTOM_DEPS
-      if opts.no_custom_deps:
-        custom_deps = None
-      bisect_utils.CreateBisectDirectoryAndSetupDepot(opts, custom_deps)
-
-      os.chdir(os.path.join(os.getcwd(), 'src'))
-
-      if not RemoveBuildFiles(opts.target_build_type):
-        raise RuntimeError('Something went wrong removing the build files.')
-
-    if not _IsPlatformSupported():
-      raise RuntimeError('Sorry, this platform isn\'t supported yet.')
-
-    # Check what source control method is being used, and create a
-    # SourceControl object if possible.
-    source_control = source_control_module.DetermineAndCreateSourceControl(opts)
-
-    if not source_control:
-      raise RuntimeError(
-          'Sorry, only the git workflow is supported at the moment.')
-
-    # gClient sync seems to fail if you're not in master branch.
-    if (not source_control.IsInProperBranch() and
-        not opts.debug_ignore_sync and
-        not opts.working_directory):
-      raise RuntimeError('You must switch to master branch to run bisection.')
-    bisect_test = BisectPerformanceMetrics(source_control, opts)
-    try:
-      bisect_results = bisect_test.Run(opts.command,
-                                       opts.bad_revision,
-                                       opts.good_revision,
-                                       opts.metric)
-      if bisect_results['error']:
-        raise RuntimeError(bisect_results['error'])
-      bisect_test.FormatAndPrintResults(bisect_results)
-      return 0
-    finally:
-      bisect_test.PerformCleanup()
-  except RuntimeError, e:
-    if opts.output_buildbot_annotations:
-      # The perf dashboard scrapes the "results" step in order to comment on
-      # bugs. If you change this, please update the perf dashboard as well.
-      bisect_utils.OutputAnnotationStepStart('Results')
-    print 'Error: %s' % e.message
-    if opts.output_buildbot_annotations:
-      bisect_utils.OutputAnnotationStepClosed()
-  return 1
-
-
-if __name__ == '__main__':
-  sys.exit(main())