Add a --startup option to generate combined traces for startup.

tools/profile_chrome/chrome_startup_controller.py

+# Copyright 2015 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.
+
+import os
+import re
+import time
+
+from pylib import flag_changer
+from pylib.perf import cache_control
+
+from profile_chrome import controllers
+
+class ChromeStartupTracingController(controllers.BaseController):
+  def __init__(self, device, package_info, cold, url):
+    self._device = device
+    self._package_info = package_info
+    self._cold = cold
+    self._url = url
+    self._trace_file = None
+    self._trace_finish_re = re.compile(r' Completed startup tracing to (.*)')
+    self._device.old_interface.StartMonitoringLogcat(clear=False)
+
+  def __repr__(self):
+    return 'Browser Startup Trace'
+
+  def _SetupTracing(self):
+    changer = flag_changer.FlagChanger(
+        self._device, self._package_info.cmdline_file)
+    changer.AddFlags(['--trace-startup'])
+    self._device.old_interface.CloseApplication(self._package_info.package)
+    if self._cold:
+      self._device.old_interface.EnableAdbRoot()
+      cache_control.CacheControl(self._device).DropRamCaches()
+    self._device.old_interface.StartActivity(
+        package=self._package_info.package,
+        activity=self._package_info.activity,
+        data=self._url,
+        extras={'create_new_tab' : True})
+
+  def _TearDownTracing(self):
+    changer = flag_changer.FlagChanger(
+        self._device, self._package_info.cmdline_file)
+    changer.RemoveFlags(['--trace-startup'])
+
+  def StartTracing(self, interval):
+    self._SetupTracing()
+    self._device.old_interface.SyncLogCat()
+
+  def StopTracing(self):
+    try:
+      self._trace_file = self._device.old_interface.WaitForLogMatch(
+          self._trace_finish_re, None, timeout=10).group(1)
+    finally:
+      self._TearDownTracing()
+
+  def PullTrace(self):
+    # Wait a bit for the browser to finish writing the trace file.
+    time.sleep(3)
+    trace_file = self._trace_file.replace('/storage/emulated/0/', '/sdcard/')
+    host_file = os.path.join(os.path.curdir, os.path.basename(trace_file))
+    self._device.PullFile(trace_file, host_file)
+    return host_file