Add a script to run the PGO benchmarks.

This is mostly a copy of https://cs.chromium.org/chromium/build/scripts/slave/recipe_modules/pgo/resources/run_benchmark.py (which will disappear)

I think that it make more sense to keep this script in the Chrome repo, so people can easily do a local PGO build.

BUG=309849

Review-Url: https://codereview.chromium.org/2368353003
Cr-Commit-Position: refs/heads/master@{#421276}

build/win/run_pgo_profiling_benchmarks.py

+# Copyright 2016 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.
+
+"""Utility script to run the benchmarks during the profiling step of a PGO
+build.
+"""
+
+import json
+import optparse
+import os
+import subprocess
+import sys
+
+# Make sure that we're running as admin, this is required to run the Telemetry
+# benchmarks.
+from win32com.shell import shell
+if not shell.IsUserAnAdmin():
+  raise Exception('This script has to be run as admin.')
+
+
+_SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
+_CHROME_BUILD_DIR = os.path.dirname(_SCRIPT_DIR)
+_CHROME_SRC_DIR = os.path.dirname(_CHROME_BUILD_DIR)
+
+
+# List of the benchmark that we run during the profiling step.
+_BENCHMARKS_TO_RUN = {
+  'blink_perf.bindings',
+  'blink_perf.canvas',
+  'blink_perf.css',
+  'blink_perf.dom',
+  'blink_perf.paint',
+  'blink_perf.svg',
+  'blink_style.top_25',
+  'dromaeo.cssqueryjquery',
+  'dromaeo.domcoreattr',
+  'dromaeo.domcoremodify',
+  'dromaeo.domcorequery',
+  'dromaeo.domcoretraverse',
+  'dromaeo.jslibattrprototype',
+  'dromaeo.jslibeventprototype',
+  'dromaeo.jslibmodifyprototype',
+  'dromaeo.jslibstyleprototype',
+  'dromaeo.jslibtraversejquery',
+  'dromaeo.jslibtraverseprototype',
+  'indexeddb_perf',
+  'media.tough_video_cases',
+  'octane',
+  'smoothness.top_25_smooth',
+  'speedometer',
+  'sunspider',
+}
+
+
+def FindPgosweep(target_cpu):
+  """Find the directory containing pgosweep.exe.
+
+  Note: |target_cpu| should be x86 or x64.
+  """
+  if target_cpu not in ('x86', 'x64'):
+    raise Exception('target_cpu should be x86 or x64.')
+  win_toolchain_json_file = os.path.join(_CHROME_BUILD_DIR,
+                                         'win_toolchain.json')
+  if not os.path.exists(win_toolchain_json_file):
+    raise Exception('The toolchain JSON file (%s) is missing.' %
+                    win_toolchain_json_file)
+  with open(win_toolchain_json_file) as temp_f:
+    toolchain_data = json.load(temp_f)
+  if not os.path.isdir(toolchain_data['path']):
+    raise Exception('The toolchain JSON file\'s "path" entry (%s) does not '
+                    'refer to a path.' % win_toolchain_json_file)
+
+  pgo_sweep_dir = os.path.join(toolchain_data['path'], 'VC', 'bin')
+  if target_cpu == 'x64':
+    pgo_sweep_dir = os.path.join(pgo_sweep_dir, 'amd64')
+
+  if not os.path.exists(os.path.join(pgo_sweep_dir, 'pgosweep.exe')):
+    raise Exception('pgosweep.exe is missing from %s.' % pgo_sweep_dir)
+
+  return pgo_sweep_dir
+
+
+def RunBenchmarks(options):
+  """Run the benchmarks."""
+  # Starts by finding the directory containing pgosweep.exe
+  pgo_sweep_dir = FindPgosweep(options.target_cpu)
+
+  # Find the run_benchmark script.
+  chrome_run_benchmark_script = os.path.join(_CHROME_SRC_DIR, 'tools',
+                                             'perf', 'run_benchmark')
+  if not os.path.exists(chrome_run_benchmark_script):
+    raise Exception('Unable to find the run_benchmark script '
+                    '(%s doesn\'t exist) ' % chrome_run_benchmark_script)
+
+  # Augment the PATH to make sure that the benchmarking script can find
+  # pgosweep.exe and its runtime libraries.
+  env = os.environ.copy()
+  env['PATH'] = str(os.pathsep.join([pgo_sweep_dir, options.build_dir,
+                                     os.environ['PATH']]))
+  env['PogoSafeMode'] = '1'
+  # Apply a scaling factor of 0.5 to the PGO profiling buffers for the 32-bit
+  # builds, without this the buffers will be too large and the process will
+  # fail to start. See crbug.com/632864#c22.
+  if options.target_cpu == 'x86':
+    env['VCPROFILE_ALLOC_SCALE'] = '0.5'
+
+  # Run all the benchmarks.
+  # TODO(sebmarchand): Make this run in parallel.
+  for benchmark in _BENCHMARKS_TO_RUN:
+    try:
+      benchmark_command = [
+          sys.executable,
+          chrome_run_benchmark_script,
+          '--browser', options.browser_type,
+        ]
+      # Automatically set the arguments to run this script on a local build.
+      if options.browser_type == 'exact':
+        benchmark_command += [
+          '--browser-executable', os.path.join(options.build_dir, 'chrome.exe')
+        ]
+      benchmark_command += [
+          '--profiler', 'win_pgo_profiler',
+          benchmark
+        ]
+      subprocess.check_call(benchmark_command, env=env)
+    except:
+      print ('Error while trying to run the %s benchmark, continuing.' %
+             benchmark)
+      continue
+
+  return 0
+
+
+def main():
+  parser = optparse.OptionParser(usage='%prog [options]')
+  parser.add_option(
+      '--browser-type', help='The browser type (to be passed to Telemetry\'s '
+                              'benchmark runner).')
+  # TODO(sebmarchand): Parse the args.gn file to automatically set this value.
+  parser.add_option('--target-cpu', help='The target\'s bitness.')
+  parser.add_option('--build-dir', help='Chrome build directory.')
+  options, _ = parser.parse_args()
+
+  if not options.target_cpu:
+    parser.error('--target-cpu is required')
+  if not options.build_dir:
+    parser.error('--build-dir is required')
+  if not options.browser_type:
+    options.browser_type = 'exact'
+
+  return RunBenchmarks(options)
+
+
+if __name__ == '__main__':
+  sys.exit(main())