Revert of Sync GN unit tests with GYP, add checking script.

tools/gn/bin/compare_test_lists.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.
-
-# This script compares the gtest test list for two different builds.
-#
-# Usage:
-#   compare_test_lists.py <build_dir_1> <build_dir_2> <binary_name>
-#
-# For example, from the "src" directory:
-#   python tools/gn/bin/compare_test_lists.py out/Debug out/gnbuild ipc_tests
-#
-# This will compile the given binary in both output directories, then extracts
-# the test lists and prints missing or extra tests between the first and the
-# second build.
-
-import os
-import subprocess
-import sys
-
-def BuildBinary(build_dir, binary_name):
-  """Builds the given binary in the given directory with Ninja.
-
-  Returns True on success."""
-  return subprocess.call(["ninja", "-C", build_dir, binary_name]) == 0
-
-
-def GetTestList(path_to_binary):
-  """Returns a set of full test names.
-
-  Each test will be of the form "Case.Test". There will be a separate line
-  for each combination of Case/Test (there are often multiple tests in each
-  case).
-
-  Throws an exception on failure."""
-  raw_output = subprocess.check_output([path_to_binary, "--gtest_list_tests"])
-  input_lines = raw_output.split('\n')
-
-  # The format of the gtest_list_tests output is:
-  # "Case1."
-  # "  Test1  # <Optional extra stuff>"
-  # "  Test2"
-  # "Case2."
-  # "  Test1"
-  case_name = ''  # Includes trailing dot.
-  test_set = set()
-  for line in input_lines:
-    if len(line) > 1:
-      if line[0] == ' ':
-        # Indented means a test in previous case.
-        test_set.add(case_name + line[:line.find('#')].strip())
-      else:
-        # New test case.
-        case_name = line.strip()
-
-  return test_set
-
-
-def PrintSetDiff(a_name, a, b_name, b, binary_name):
-  """Prints the test list difference between the given sets a and b.
-
-  a_name and b_name will be used to refer to the directories of the two sets,
-  and the binary name will be shown as the source of the output."""
-
-  a_not_b = list(a - b)
-  if len(a_not_b):
-    print "\n", binary_name, "tests in", a_name, "but not", b_name
-    a_not_b.sort()
-    for cur in a_not_b:
-      print "  ", cur
-
-  b_not_a = list(b - a)
-  if len(b_not_a):
-    print "\n", binary_name, "tests in", b_name, "but not", a_name
-    b_not_a.sort()
-    for cur in b_not_a:
-      print "  ", cur
-
-  if len(a_not_b) == 0 and len(b_not_a) == 0:
-    print "\nTests match!"
-
-
-def Run(a_dir, b_dir, binary_name):
-  if not BuildBinary(a_dir, binary_name):
-    print "Building", binary_name, "in", a_dir, "failed"
-    return 1
-  if not BuildBinary(b_dir, binary_name):
-    print "Building", binary_name, "in", b_dir, "failed"
-    return 1
-
-  a_tests = GetTestList(os.path.join(a_dir, binary_name))
-  b_tests = GetTestList(os.path.join(b_dir, binary_name))
-
-  PrintSetDiff(a_dir, a_tests, b_dir, b_tests, binary_name)
-
-
-if len(sys.argv) != 4:
-  print "Usage: compare_test_lists.py <build_dir_1> <build_dir_2> " \
-      "<test_binary_name>"
-  sys.exit(1)
-sys.exit(Run(sys.argv[1], sys.argv[2], sys.argv[3]))