Update idlsync.py to pull in dependencies required for chrome api generation.

third_party/chrome/tools/bisect-builds.py

+#!/usr/bin/env python
+# Copyright (c) 2012 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.
+
+"""Snapshot Build Bisect Tool
+
+This script bisects a snapshot archive using binary search. It starts at
+a bad revision (it will try to guess HEAD) and asks for a last known-good
+revision. It will then binary search across this revision range by downloading,
+unzipping, and opening Chromium for you. After testing the specific revision,
+it will ask you whether it is good or bad before continuing the search.
+"""
+
+# The root URL for storage.
+BASE_URL = 'http://commondatastorage.googleapis.com/chromium-browser-snapshots'
+
+# The root URL for official builds.
+OFFICIAL_BASE_URL = 'http://master.chrome.corp.google.com/official_builds'
+
+# Changelogs URL.
+CHANGELOG_URL = 'http://build.chromium.org/f/chromium/' \
+                'perf/dashboard/ui/changelog.html?url=/trunk/src&range=%d%%3A%d'
+
+# Official Changelogs URL.
+OFFICIAL_CHANGELOG_URL = 'http://omahaproxy.appspot.com/'\
+                         'changelog?old_version=%s&new_version=%s'
+
+# DEPS file URL.
+DEPS_FILE= 'http://src.chromium.org/viewvc/chrome/trunk/src/DEPS?revision=%d'
+# WebKit Changelogs URL.
+WEBKIT_CHANGELOG_URL = 'http://trac.webkit.org/log/' \
+                       'trunk/?rev=%d&stop_rev=%d&verbose=on&limit=10000'
+
+DONE_MESSAGE_GOOD_MIN = 'You are probably looking for a change made after %s ' \
+                        '(known good), but no later than %s (first known bad).'
+DONE_MESSAGE_GOOD_MAX = 'You are probably looking for a change made after %s ' \
+                        '(known bad), but no later than %s (first known good).'
+
+###############################################################################
+
+import math
+import optparse
+import os
+import pipes
+import re
+import shutil
+import subprocess
+import sys
+import tempfile
+import threading
+import urllib
+from distutils.version import LooseVersion
+from xml.etree import ElementTree
+import zipfile
+
+
+class PathContext(object):
+  """A PathContext is used to carry the information used to construct URLs and
+  paths when dealing with the storage server and archives."""
+  def __init__(self, platform, good_revision, bad_revision, is_official):
+    super(PathContext, self).__init__()
+    # Store off the input parameters.
+    self.platform = platform  # What's passed in to the '-a/--archive' option.
+    self.good_revision = good_revision
+    self.bad_revision = bad_revision
+    self.is_official = is_official
+
+    # The name of the ZIP file in a revision directory on the server.
+    self.archive_name = None
+
+    # Set some internal members:
+    #   _listing_platform_dir = Directory that holds revisions. Ends with a '/'.
+    #   _archive_extract_dir = Uncompressed directory in the archive_name file.
+    #   _binary_name = The name of the executable to run.
+    if self.platform == 'linux' or self.platform == 'linux64':
+      self._binary_name = 'chrome'
+    elif self.platform == 'mac':
+      self.archive_name = 'chrome-mac.zip'
+      self._archive_extract_dir = 'chrome-mac'
+    elif self.platform == 'win':
+      self.archive_name = 'chrome-win32.zip'
+      self._archive_extract_dir = 'chrome-win32'
+      self._binary_name = 'chrome.exe'
+    else:
+      raise Exception('Invalid platform: %s' % self.platform)
+
+    if is_official:
+      if self.platform == 'linux':
+        self._listing_platform_dir = 'lucid32bit/'
+        self.archive_name = 'chrome-lucid32bit.zip'
+        self._archive_extract_dir = 'chrome-lucid32bit'
+      elif self.platform == 'linux64':
+        self._listing_platform_dir = 'lucid64bit/'
+        self.archive_name = 'chrome-lucid64bit.zip'
+        self._archive_extract_dir = 'chrome-lucid64bit'
+      elif self.platform == 'mac':
+        self._listing_platform_dir = 'mac/'
+        self._binary_name = 'Google Chrome.app/Contents/MacOS/Google Chrome'
+      elif self.platform == 'win':
+        self._listing_platform_dir = 'win/'
+    else:
+      if self.platform == 'linux' or self.platform == 'linux64':
+        self.archive_name = 'chrome-linux.zip'
+        self._archive_extract_dir = 'chrome-linux'
+        if self.platform == 'linux':
+          self._listing_platform_dir = 'Linux/'
+        elif self.platform == 'linux64':
+          self._listing_platform_dir = 'Linux_x64/'
+      elif self.platform == 'mac':
+        self._listing_platform_dir = 'Mac/'
+        self._binary_name = 'Chromium.app/Contents/MacOS/Chromium'
+      elif self.platform == 'win':
+        self._listing_platform_dir = 'Win/'
+
+  def GetListingURL(self, marker=None):
+    """Returns the URL for a directory listing, with an optional marker."""
+    marker_param = ''
+    if marker:
+      marker_param = '&marker=' + str(marker)
+    return BASE_URL + '/?delimiter=/&prefix=' + self._listing_platform_dir + \
+        marker_param
+
+  def GetDownloadURL(self, revision):
+    """Gets the download URL for a build archive of a specific revision."""
+    if self.is_official:
+      return "%s/%s/%s%s" % (
+          OFFICIAL_BASE_URL, revision, self._listing_platform_dir,
+          self.archive_name)
+    else:
+      return "%s/%s%s/%s" % (
+          BASE_URL, self._listing_platform_dir, revision, self.archive_name)
+
+  def GetLastChangeURL(self):
+    """Returns a URL to the LAST_CHANGE file."""
+    return BASE_URL + '/' + self._listing_platform_dir + 'LAST_CHANGE'
+
+  def GetLaunchPath(self):
+    """Returns a relative path (presumably from the archive extraction location)
+    that is used to run the executable."""
+    return os.path.join(self._archive_extract_dir, self._binary_name)
+
+  def ParseDirectoryIndex(self):
+    """Parses the Google Storage directory listing into a list of revision
+    numbers."""
+
+    def _FetchAndParse(url):
+      """Fetches a URL and returns a 2-Tuple of ([revisions], next-marker). If
+      next-marker is not None, then the listing is a partial listing and another
+      fetch should be performed with next-marker being the marker= GET
+      parameter."""
+      handle = urllib.urlopen(url)
+      document = ElementTree.parse(handle)
+
+      # All nodes in the tree are namespaced. Get the root's tag name to extract
+      # the namespace. Etree does namespaces as |{namespace}tag|.
+      root_tag = document.getroot().tag
+      end_ns_pos = root_tag.find('}')
+      if end_ns_pos == -1:
+        raise Exception("Could not locate end namespace for directory index")
+      namespace = root_tag[:end_ns_pos + 1]
+
+      # Find the prefix (_listing_platform_dir) and whether or not the list is
+      # truncated.
+      prefix_len = len(document.find(namespace + 'Prefix').text)
+      next_marker = None
+      is_truncated = document.find(namespace + 'IsTruncated')
+      if is_truncated is not None and is_truncated.text.lower() == 'true':
+        next_marker = document.find(namespace + 'NextMarker').text
+
+      # Get a list of all the revisions.
+      all_prefixes = document.findall(namespace + 'CommonPrefixes/' +
+                                      namespace + 'Prefix')
+      # The <Prefix> nodes have content of the form of
+      # |_listing_platform_dir/revision/|. Strip off the platform dir and the
+      # trailing slash to just have a number.
+      revisions = []
+      for prefix in all_prefixes:
+        revnum = prefix.text[prefix_len:-1]
+        try:
+          revnum = int(revnum)
+          revisions.append(revnum)
+        except ValueError:
+          pass
+      return (revisions, next_marker)
+      
+    # Fetch the first list of revisions.
+    (revisions, next_marker) = _FetchAndParse(self.GetListingURL())
+
+    # If the result list was truncated, refetch with the next marker. Do this
+    # until an entire directory listing is done.
+    while next_marker:
+      next_url = self.GetListingURL(next_marker)
+      (new_revisions, next_marker) = _FetchAndParse(next_url)
+      revisions.extend(new_revisions)
+    return revisions
+
+  def GetRevList(self):
+    """Gets the list of revision numbers between self.good_revision and
+    self.bad_revision."""
+    # Download the revlist and filter for just the range between good and bad.
+    minrev = min(self.good_revision, self.bad_revision)
+    maxrev = max(self.good_revision, self.bad_revision)
+    revlist = map(int, self.ParseDirectoryIndex())
+    revlist = [x for x in revlist if x >= int(minrev) and x <= int(maxrev)]
+    revlist.sort()
+    return revlist
+
+  def GetOfficialBuildsList(self):
+    """Gets the list of official build numbers between self.good_revision and
+    self.bad_revision."""
+    # Download the revlist and filter for just the range between good and bad.
+    minrev = min(self.good_revision, self.bad_revision)
+    maxrev = max(self.good_revision, self.bad_revision)
+    handle = urllib.urlopen(OFFICIAL_BASE_URL)
+    dirindex = handle.read()
+    handle.close()
+    build_numbers = re.findall(r'<a href="([0-9][0-9].*)/">', dirindex)
+    final_list = []
+    i = 0
+    parsed_build_numbers = [LooseVersion(x) for x in build_numbers]
+    for build_number in sorted(parsed_build_numbers):
+      path = OFFICIAL_BASE_URL + '/' + str(build_number) + '/' + \
+             self._listing_platform_dir + self.archive_name
+      i = i + 1
+      try:
+        connection = urllib.urlopen(path)
+        connection.close()
+        if build_number > maxrev:
+          break
+        if build_number >= minrev:
+          final_list.append(str(build_number))
+      except urllib.HTTPError, e:
+        pass
+    return final_list
+
+def UnzipFilenameToDir(filename, dir):
+  """Unzip |filename| to directory |dir|."""
+  cwd = os.getcwd()
+  if not os.path.isabs(filename):
+    filename = os.path.join(cwd, filename)
+  zf = zipfile.ZipFile(filename)
+  # Make base.
+  if not os.path.isdir(dir):
+    os.mkdir(dir)
+  os.chdir(dir)
+  # Extract files.
+  for info in zf.infolist():
+    name = info.filename
+    if name.endswith('/'):  # dir
+      if not os.path.isdir(name):
+        os.makedirs(name)
+    else:  # file
+      dir = os.path.dirname(name)
+      if not os.path.isdir(dir):
+        os.makedirs(dir)
+      out = open(name, 'wb')
+      out.write(zf.read(name))
+      out.close()
+    # Set permissions. Permission info in external_attr is shifted 16 bits.
+    os.chmod(name, info.external_attr >> 16L)
+  os.chdir(cwd)
+
+
+def FetchRevision(context, rev, filename, quit_event=None, progress_event=None):
+  """Downloads and unzips revision |rev|.
+  @param context A PathContext instance.
+  @param rev The Chromium revision number/tag to download.
+  @param filename The destination for the downloaded file.
+  @param quit_event A threading.Event which will be set by the master thread to
+                    indicate that the download should be aborted.
+  @param progress_event A threading.Event which will be set by the master thread
+                    to indicate that the progress of the download should be
+                    displayed.
+  """
+  def ReportHook(blocknum, blocksize, totalsize):
+    if quit_event and quit_event.isSet():
+      raise RuntimeError("Aborting download of revision %s" % str(rev))
+    if progress_event and progress_event.isSet():
+      size = blocknum * blocksize
+      if totalsize == -1:  # Total size not known.
+        progress = "Received %d bytes" % size
+      else:
+        size = min(totalsize, size)
+        progress = "Received %d of %d bytes, %.2f%%" % (
+            size, totalsize, 100.0 * size / totalsize)
+      # Send a \r to let all progress messages use just one line of output.
+      sys.stdout.write("\r" + progress)
+      sys.stdout.flush()
+
+  download_url = context.GetDownloadURL(rev)
+  try:
+    urllib.urlretrieve(download_url, filename, ReportHook)
+    if progress_event and progress_event.isSet():
+      print
+  except RuntimeError, e:
+    pass
+
+
+def RunRevision(context, revision, zipfile, profile, num_runs, args):
+  """Given a zipped revision, unzip it and run the test."""
+  print "Trying revision %s..." % str(revision)
+
+  # Create a temp directory and unzip the revision into it.
+  cwd = os.getcwd()
+  tempdir = tempfile.mkdtemp(prefix='bisect_tmp')
+  UnzipFilenameToDir(zipfile, tempdir)
+  os.chdir(tempdir)
+
+  # Run the build as many times as specified.
+  testargs = [context.GetLaunchPath(), '--user-data-dir=%s' % profile] + args
+  # The sandbox must be run as root on Official Chrome, so bypass it.
+  if context.is_official and (context.platform == 'linux' or
+      context.platform == 'linux64'):
+    testargs.append('--no-sandbox')
+
+  for i in range(0, num_runs):
+    subproc = subprocess.Popen(testargs,
+                               bufsize=-1,
+                               stdout=subprocess.PIPE,
+                               stderr=subprocess.PIPE)
+    (stdout, stderr) = subproc.communicate()
+
+  os.chdir(cwd)
+  try:
+    shutil.rmtree(tempdir, True)
+  except Exception, e:
+    pass
+
+  return (subproc.returncode, stdout, stderr)
+
+
+def AskIsGoodBuild(rev, official_builds, status, stdout, stderr):
+  """Ask the user whether build |rev| is good or bad."""
+  # Loop until we get a response that we can parse.
+  while True:
+    response = raw_input('Revision %s is [(g)ood/(b)ad/(u)nknown/(q)uit]: ' %
+                         str(rev))
+    if response and response in ('g', 'b', 'u'):
+      return response
+    if response and response == 'q':
+      raise SystemExit()
+
+
+class DownloadJob(object):
+  """DownloadJob represents a task to download a given Chromium revision."""
+  def __init__(self, context, name, rev, zipfile):
+    super(DownloadJob, self).__init__()
+    # Store off the input parameters.
+    self.context = context
+    self.name = name
+    self.rev = rev
+    self.zipfile = zipfile
+    self.quit_event = threading.Event()
+    self.progress_event = threading.Event()
+
+  def Start(self):
+    """Starts the download."""
+    fetchargs = (self.context,
+                 self.rev,
+                 self.zipfile,
+                 self.quit_event,
+                 self.progress_event)
+    self.thread = threading.Thread(target=FetchRevision,
+                                   name=self.name,
+                                   args=fetchargs)
+    self.thread.start()
+
+  def Stop(self):
+    """Stops the download which must have been started previously."""
+    self.quit_event.set()
+    self.thread.join()
+    os.unlink(self.zipfile)
+
+  def WaitFor(self):
+    """Prints a message and waits for the download to complete. The download
+    must have been started previously."""
+    print "Downloading revision %s..." % str(self.rev)
+    self.progress_event.set()  # Display progress of download.
+    self.thread.join()
+
+
+def Bisect(platform,
+           official_builds,
+           good_rev=0,
+           bad_rev=0,
+           num_runs=1,
+           try_args=(),
+           profile=None,
+           evaluate=AskIsGoodBuild):
+  """Given known good and known bad revisions, run a binary search on all
+  archived revisions to determine the last known good revision.
+
+  @param platform Which build to download/run ('mac', 'win', 'linux64', etc.).
+  @param official_builds Specify build type (Chromium or Official build).
+  @param good_rev Number/tag of the known good revision.
+  @param bad_rev Number/tag of the known bad revision.
+  @param num_runs Number of times to run each build for asking good/bad.
+  @param try_args A tuple of arguments to pass to the test application.
+  @param profile The name of the user profile to run with.
+  @param evaluate A function which returns 'g' if the argument build is good,
+                  'b' if it's bad or 'u' if unknown.
+
+  Threading is used to fetch Chromium revisions in the background, speeding up
+  the user's experience. For example, suppose the bounds of the search are
+  good_rev=0, bad_rev=100. The first revision to be checked is 50. Depending on
+  whether revision 50 is good or bad, the next revision to check will be either
+  25 or 75. So, while revision 50 is being checked, the script will download
+  revisions 25 and 75 in the background. Once the good/bad verdict on rev 50 is
+  known:
+
+    - If rev 50 is good, the download of rev 25 is cancelled, and the next test
+      is run on rev 75.
+
+    - If rev 50 is bad, the download of rev 75 is cancelled, and the next test
+      is run on rev 25.
+  """
+
+  if not profile:
+    profile = 'profile'
+
+  context = PathContext(platform, good_rev, bad_rev, official_builds)
+  cwd = os.getcwd()
+
+
+
+  print "Downloading list of known revisions..."
+  _GetDownloadPath = lambda rev: os.path.join(cwd,
+      '%s-%s' % (str(rev), context.archive_name))
+  if official_builds:
+    revlist = context.GetOfficialBuildsList()
+  else:
+    revlist = context.GetRevList()
+
+  # Get a list of revisions to bisect across.
+  if len(revlist) < 2:  # Don't have enough builds to bisect.
+    msg = 'We don\'t have enough builds to bisect. revlist: %s' % revlist
+    raise RuntimeError(msg)
+
+  # Figure out our bookends and first pivot point; fetch the pivot revision.
+  minrev = 0
+  maxrev = len(revlist) - 1
+  pivot = maxrev / 2
+  rev = revlist[pivot]
+  zipfile = _GetDownloadPath(rev)
+  fetch = DownloadJob(context, 'initial_fetch', rev, zipfile)
+  fetch.Start()
+  fetch.WaitFor()
+
+  # Binary search time!
+  while fetch and fetch.zipfile and maxrev - minrev > 1:
+    if bad_rev < good_rev:
+      min_str, max_str = "bad", "good"
+    else:
+      min_str, max_str = "good", "bad"
+    print 'Bisecting range [%s (%s), %s (%s)].' % (revlist[minrev], min_str, \
+                                                   revlist[maxrev], max_str)
+
+    # Pre-fetch next two possible pivots
+    #   - down_pivot is the next revision to check if the current revision turns
+    #     out to be bad.
+    #   - up_pivot is the next revision to check if the current revision turns
+    #     out to be good.
+    down_pivot = int((pivot - minrev) / 2) + minrev
+    down_fetch = None
+    if down_pivot != pivot and down_pivot != minrev:
+      down_rev = revlist[down_pivot]
+      down_fetch = DownloadJob(context, 'down_fetch', down_rev,
+                               _GetDownloadPath(down_rev))
+      down_fetch.Start()
+
+    up_pivot = int((maxrev - pivot) / 2) + pivot
+    up_fetch = None
+    if up_pivot != pivot and up_pivot != maxrev:
+      up_rev = revlist[up_pivot]
+      up_fetch = DownloadJob(context, 'up_fetch', up_rev,
+                             _GetDownloadPath(up_rev))
+      up_fetch.Start()
+
+    # Run test on the pivot revision.
+    status = None
+    stdout = None
+    stderr = None
+    try:
+      (status, stdout, stderr) = RunRevision(context,
+                                             rev,
+                                             fetch.zipfile,
+                                             profile,
+                                             num_runs,
+                                             try_args)
+    except Exception, e:
+      print >>sys.stderr, e
+    fetch.Stop()
+    fetch = None
+
+    # Call the evaluate function to see if the current revision is good or bad.
+    # On that basis, kill one of the background downloads and complete the
+    # other, as described in the comments above.
+    try:
+      answer = evaluate(rev, official_builds, status, stdout, stderr)
+      if answer == 'g' and good_rev < bad_rev or \
+          answer == 'b' and bad_rev < good_rev:
+        minrev = pivot
+        if down_fetch:
+          down_fetch.Stop()  # Kill the download of the older revision.
+        if up_fetch:
+          up_fetch.WaitFor()
+          pivot = up_pivot
+          fetch = up_fetch
+      elif answer == 'b' and good_rev < bad_rev or \
+          answer == 'g' and bad_rev < good_rev:
+        maxrev = pivot
+        if up_fetch:
+          up_fetch.Stop()  # Kill the download of the newer revision.
+        if down_fetch:
+          down_fetch.WaitFor()
+          pivot = down_pivot
+          fetch = down_fetch
+      elif answer == 'u':
+        # Nuke the revision from the revlist and choose a new pivot.
+        revlist.pop(pivot)
+        maxrev -= 1  # Assumes maxrev >= pivot.
+
+        if maxrev - minrev > 1:
+          # Alternate between using down_pivot or up_pivot for the new pivot
+          # point, without affecting the range. Do this instead of setting the
+          # pivot to the midpoint of the new range because adjacent revisions
+          # are likely affected by the same issue that caused the (u)nknown
+          # response.
+          if up_fetch and down_fetch:
+            fetch = [up_fetch, down_fetch][len(revlist) % 2]
+          elif up_fetch:
+            fetch = up_fetch
+          else:
+            fetch = down_fetch
+          fetch.WaitFor()
+          if fetch == up_fetch:
+            pivot = up_pivot - 1  # Subtracts 1 because revlist was resized.
+          else:
+            pivot = down_pivot
+          zipfile = fetch.zipfile
+
+        if down_fetch and fetch != down_fetch:
+          down_fetch.Stop()
+        if up_fetch and fetch != up_fetch:
+          up_fetch.Stop()
+      else:
+        assert False, "Unexpected return value from evaluate(): " + answer
+    except SystemExit:
+      print "Cleaning up..."
+      for f in [_GetDownloadPath(revlist[down_pivot]),
+                _GetDownloadPath(revlist[up_pivot])]:
+        try:
+          os.unlink(f)
+        except OSError:
+          pass
+      sys.exit(0)
+
+    rev = revlist[pivot]
+
+  return (revlist[minrev], revlist[maxrev])
+
+
+def GetWebKitRevisionForChromiumRevision(rev):
+  """Returns the webkit revision that was in chromium's DEPS file at
+  chromium revision |rev|."""
+  # . doesn't match newlines without re.DOTALL, so this is safe.
+  webkit_re = re.compile(r'webkit_revision.:\D*(\d+)')
+  url = urllib.urlopen(DEPS_FILE % rev)
+  m = webkit_re.search(url.read())
+  url.close()
+  if m:
+    return int(m.group(1))
+  else:
+    raise Exception('Could not get webkit revision for cr rev %d' % rev)
+
+
+def GetChromiumRevision(url):
+  """Returns the chromium revision read from given URL."""
+  try:
+    # Location of the latest build revision number
+    return int(urllib.urlopen(url).read())
+  except Exception, e:
+    print('Could not determine latest revision. This could be bad...')
+    return 999999999
+
+
+def main():
+  usage = ('%prog [options] [-- chromium-options]\n'
+           'Perform binary search on the snapshot builds to find a minimal '
+           'range of revisions where a behavior change happened. The '
+           'behaviors are described as "good" and "bad". '
+           'It is NOT assumed that the behavior of the later revision is '
+           'the bad one.\n'
+           '\n'
+           'Tip: add "-- --no-first-run" to bypass the first run prompts.')
+  parser = optparse.OptionParser(usage=usage)
+  # Strangely, the default help output doesn't include the choice list.
+  choices = ['mac', 'win', 'linux', 'linux64']
+            # linux-chromiumos lacks a continuous archive http://crbug.com/78158
+  parser.add_option('-a', '--archive',
+                    choices = choices,
+                    help = 'The buildbot archive to bisect [%s].' %
+                           '|'.join(choices))
+  parser.add_option('-o', action="store_true", dest='official_builds',
+                    help = 'Bisect across official ' +
+                    'Chrome builds (internal only) instead of ' +
+                    'Chromium archives.')
+  parser.add_option('-b', '--bad', type = 'str',
+                    help = 'A bad revision to start bisection. ' +
+                    'May be earlier or later than the good revision. ' +
+                    'Default is HEAD.')
+  parser.add_option('-g', '--good', type = 'str',
+                    help = 'A good revision to start bisection. ' +
+                    'May be earlier or later than the bad revision. ' +
+                    'Default is 0.')
+  parser.add_option('-p', '--profile', '--user-data-dir', type = 'str',
+                    help = 'Profile to use; this will not reset every run. ' +
+                    'Defaults to a clean profile.', default = 'profile')
+  parser.add_option('-t', '--times', type = 'int',
+                    help = 'Number of times to run each build before asking ' +
+                    'if it\'s good or bad. Temporary profiles are reused.',
+                    default = 1)
+  (opts, args) = parser.parse_args()
+
+  if opts.archive is None:
+    print 'Error: missing required parameter: --archive'
+    print
+    parser.print_help()
+    return 1
+
+  # Create the context. Initialize 0 for the revisions as they are set below.
+  context = PathContext(opts.archive, 0, 0, opts.official_builds)
+  # Pick a starting point, try to get HEAD for this.
+  if opts.bad:
+    bad_rev = opts.bad
+  else:
+    bad_rev = '999.0.0.0'
+    if not opts.official_builds:
+      bad_rev = GetChromiumRevision(context.GetLastChangeURL())
+
+  # Find out when we were good.
+  if opts.good:
+    good_rev = opts.good
+  else:
+    good_rev = '0.0.0.0' if opts.official_builds else 0
+
+  if opts.official_builds:
+    good_rev = LooseVersion(good_rev)
+    bad_rev = LooseVersion(bad_rev)
+  else:
+    good_rev = int(good_rev)
+    bad_rev = int(bad_rev)
+
+  if opts.times < 1:
+    print('Number of times to run (%d) must be greater than or equal to 1.' %
+          opts.times)
+    parser.print_help()
+    return 1
+
+  (min_chromium_rev, max_chromium_rev) = Bisect(
+      opts.archive, opts.official_builds, good_rev, bad_rev, opts.times, args,
+      opts.profile)
+
+  # Get corresponding webkit revisions.
+  try:
+    min_webkit_rev = GetWebKitRevisionForChromiumRevision(min_chromium_rev)
+    max_webkit_rev = GetWebKitRevisionForChromiumRevision(max_chromium_rev)
+  except Exception, e:
+    # Silently ignore the failure.
+    min_webkit_rev, max_webkit_rev = 0, 0
+
+  # We're done. Let the user know the results in an official manner.
+  if good_rev > bad_rev:
+    print DONE_MESSAGE_GOOD_MAX % (str(min_chromium_rev), str(max_chromium_rev))
+  else:
+    print DONE_MESSAGE_GOOD_MIN % (str(min_chromium_rev), str(max_chromium_rev))
+
+  if min_webkit_rev != max_webkit_rev:
+    print 'WEBKIT CHANGELOG URL:'
+    print '  ' + WEBKIT_CHANGELOG_URL % (max_webkit_rev, min_webkit_rev)
+  print 'CHANGELOG URL:'
+  if opts.official_builds:
+    print OFFICIAL_CHANGELOG_URL % (min_chromium_rev, max_chromium_rev)
+  else:
+    print '  ' + CHANGELOG_URL % (min_chromium_rev, max_chromium_rev)
+
+if __name__ == '__main__':
+  sys.exit(main())