Hi Simon,

  As we discussed, here is the CL to update DEPS file with dependency respository revision and sending diff text to tryserver. This doesn't include diving into dependency repos eg v8 bleeding.Before proceeding further on this I would like to get your initial feedback on this.

thank you,
BUG=
NOTRY=true

Review URL: https://codereview.chromium.org/196603014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262579 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 317 insertions, 62 deletions

diff --git a/tools/bisect-perf-regression.py b/tools/bisect-perf-regression.py
index 9deeef3..0323b73 100755
--- a/tools/bisect-perf-regression.py
+++ b/tools/bisect-perf-regression.py
@@ -38,7 +38,7 @@ An example usage (using git hashes):
 import copy
 import datetime
 import errno
-import imp
+import hashlib
 import math
 import optparse
 import os
@@ -51,15 +51,11 @@ import sys
 import time
 import zipfile
 
+sys.path.append(os.path.join(os.path.dirname(__file__), 'telemetry'))
+
 import bisect_utils
 import post_perf_builder_job
-
-
-try:
-  from telemetry.page import cloud_storage
-except ImportError:
-  sys.path.append(os.path.join(os.path.dirname(sys.argv[0]), 'telemetry'))
-  from telemetry.page import cloud_storage
+from telemetry.page import cloud_storage
 
 # The additional repositories that might need to be bisected.
 # If the repository has any dependant repositories (such as skia/src needs
@@ -72,20 +68,23 @@ except ImportError:
 #   repository in svn.
 # svn: 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 varible 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='
+    'viewvc': 'http://src.chromium.org/viewvc/chrome?view=revision&revision=',
+    'deps_var': None
   },
   'webkit' : {
     "src" : "src/third_party/WebKit",
     "recurse" : True,
     "depends" : None,
     "from" : ['chromium'],
-    'viewvc': 'http://src.chromium.org/viewvc/blink?view=revision&revision='
+    'viewvc': 'http://src.chromium.org/viewvc/blink?view=revision&revision=',
+    'deps_var': 'webkit_revision'
   },
   'angle' : {
     "src" : "src/third_party/angle",
@@ -94,6 +93,7 @@ DEPOT_DEPS_NAME = {
     "depends" : None,
     "from" : ['chromium'],
     "platform": 'nt',
+    'deps_var': 'angle_revision'
   },
   'v8' : {
     "src" : "src/v8",
@@ -102,6 +102,7 @@ DEPOT_DEPS_NAME = {
     "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",
@@ -110,6 +111,7 @@ DEPOT_DEPS_NAME = {
     "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",
@@ -118,6 +120,7 @@ DEPOT_DEPS_NAME = {
     "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",
@@ -126,6 +129,7 @@ DEPOT_DEPS_NAME = {
     "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",
@@ -134,6 +138,7 @@ DEPOT_DEPS_NAME = {
     "depends" : None,
     "from" : ['chromium'],
     'viewvc': 'https://code.google.com/p/skia/source/detail?r=',
+    'deps_var': 'None'
   },
 }
 
@@ -151,6 +156,26 @@ BUILD_RESULT_SUCCEED = 0
 BUILD_RESULT_FAIL = 1
 BUILD_RESULT_SKIPPED = 2
 
+# Maximum time in seconds to wait after posting build request to tryserver.
+# TODO: Change these values based on the actual time taken by buildbots on
+# the tryserver.
+MAX_MAC_BUILD_TIME = 7200
+MAX_WIN_BUILD_TIME = 7200
+MAX_LINUX_BUILD_TIME = 7200
+
+# 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 tryserver.
+# When a build requested is posted with a patch, bisect builders on tryserver,
+# 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
+"""
 
 def _AddAdditionalDepotInfo(depot_info):
   """Adds additional depot info to the global depot variables."""
@@ -315,7 +340,12 @@ def IsMac():
   return sys.platform.startswith('darwin')
 
 
-def GetZipFileName(build_revision=None, target_arch='ia32'):
+def GetSHA1HexDigest(contents):
+  """Returns secured hash containing hexadecimal for the given contents."""
+  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."""
@@ -334,10 +364,12 @@ def GetZipFileName(build_revision=None, target_arch='ia32'):
   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_arch='ia32'):
+def GetRemoteBuildPath(build_revision, target_arch='ia32', patch_sha=None):
   """Compute the url to download the build from."""
   def GetGSRootFolderName():
     """Gets Google Cloud Storage root folder names"""
@@ -351,7 +383,7 @@ def GetRemoteBuildPath(build_revision, target_arch='ia32'):
       return 'Mac Builder'
     raise NotImplementedError('Unsupported Platform "%s".' % sys.platform)
 
-  base_filename = GetZipFileName(build_revision, target_arch)
+  base_filename = GetZipFileName(build_revision, target_arch, patch_sha)
   builder_folder = GetGSRootFolderName()
   return '%s/%s' % (builder_folder, base_filename)
 
@@ -377,10 +409,10 @@ def FetchFromCloudStorage(bucket_name, source_path, destination_path):
     else:
       print ('File gs://%s/%s not found in cloud storage.' % (
           bucket_name, source_path))
-  except e:
+  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)
+      os.remove(target_file)
   return False
 
 
@@ -565,6 +597,28 @@ def BuildWithVisualStudio(targets):
   return not return_code
 
 
+def WriteStringToFile(text, file_name):
+  with open(file_name, "w") as f:
+    f.write(text)
+
+
+def ReadStringFromFile(file_name):
+  with open(file_name) as f:
+    return f.read()
+
+
+def ChangeBackslashToSlashInPatch(diff_text):
+  """Formats file paths in the given text to unix-style paths."""
+  if diff_text:
+    diff_lines = diff_text.split('\n')
+    for i in range(len(diff_lines)):
+      if (diff_lines[i].startswith('--- ') or
+          diff_lines[i].startswith('+++ ')):
+        diff_lines[i] = diff_lines[i].replace('\\', '/')
+    return '\n'.join(diff_lines)
+  return None
+
+
 class Builder(object):
   """Builder is used by the bisect script to build relevant targets and deploy.
   """
@@ -979,7 +1033,7 @@ class GitSourceControl(SourceControl):
 
     return log_output == "master"
 
-  def SVNFindRev(self, revision):
+  def SVNFindRev(self, revision, cwd=None):
     """Maps directly to the 'git svn find-rev' command.
 
     Args:
@@ -991,7 +1045,7 @@ class GitSourceControl(SourceControl):
 
     cmd = ['svn', 'find-rev', revision]
 
-    output = CheckRunGit(cmd)
+    output = CheckRunGit(cmd, cwd)
     svn_revision = output.strip()
 
     if IsStringInt(svn_revision):
@@ -1042,7 +1096,7 @@ class GitSourceControl(SourceControl):
       True if successful.
     """
     # Reset doesn't seem to return 0 on success.
-    RunGit(['reset', 'HEAD', bisect_utils.FILE_DEPS_GIT])
+    RunGit(['reset', 'HEAD', file_name])
 
     return not RunGit(['checkout', bisect_utils.FILE_DEPS_GIT])[1]
 
@@ -1173,7 +1227,7 @@ class BisectPerformanceMetrics(object):
                 bleeding_edge_revision, 'v8_bleeding_edge', 1,
                 cwd=v8_bleeding_edge_dir)
             return git_revision
-          except IndexError, ValueError:
+          except (IndexError, ValueError):
             pass
 
         if not git_revision:
@@ -1252,12 +1306,12 @@ class BisectPerformanceMetrics(object):
               locals['deps'].has_key(DEPOT_DEPS_NAME[d]['src_old'])):
             if locals['deps'].has_key(DEPOT_DEPS_NAME[d]['src']):
               re_results = rxp.search(locals['deps'][DEPOT_DEPS_NAME[d]['src']])
-              self.depot_cwd[d] =\
+              self.depot_cwd[d] = \
                   os.path.join(self.src_cwd, DEPOT_DEPS_NAME[d]['src'][4:])
             elif locals['deps'].has_key(DEPOT_DEPS_NAME[d]['src_old']):
-              re_results =\
+              re_results = \
                   rxp.search(locals['deps'][DEPOT_DEPS_NAME[d]['src_old']])
-              self.depot_cwd[d] =\
+              self.depot_cwd[d] = \
                   os.path.join(self.src_cwd, DEPOT_DEPS_NAME[d]['src_old'][4:])
 
             if re_results:
@@ -1276,7 +1330,7 @@ class BisectPerformanceMetrics(object):
              CROS_CHROMEOS_PATTERN]
       (output, return_code) = RunProcessAndRetrieveOutput(cmd)
 
-      assert not return_code, 'An error occurred while running'\
+      assert not return_code, 'An error occurred while running' \
                               ' "%s"' % ' '.join(cmd)
 
       if len(output) > CROS_CHROMEOS_PATTERN:
@@ -1291,7 +1345,7 @@ class BisectPerformanceMetrics(object):
           version = contents[2]
 
           if contents[3] != '0':
-            warningText = 'Chrome version: %s.%s but using %s.0 to bisect.' %\
+            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)
@@ -1334,7 +1388,7 @@ class BisectPerformanceMetrics(object):
       return destination_dir
     return None
 
-  def DownloadCurrentBuild(self, revision, build_type='Release'):
+  def DownloadCurrentBuild(self, revision, build_type='Release', patch=None):
     """Download the build archive for the given revision.
 
     Args:
@@ -1344,38 +1398,53 @@ class BisectPerformanceMetrics(object):
     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})
+
+    # Source archive file path on cloud storage.
+    source_file = GetRemoteBuildPath(revision, self.opts.target_arch, patch_sha)
+
+    # Get Build output directory
     abs_build_dir = os.path.abspath(
         self.builder.GetBuildOutputDirectory(self.opts, self.src_cwd))
-    target_build_output_dir = os.path.join(abs_build_dir, build_type)
-    # Get build target architecture.
-    build_arch = self.opts.target_arch
-    # File path of the downloaded archive file.
-    archive_file_dest = os.path.join(abs_build_dir,
-                                     GetZipFileName(revision, build_arch))
-    remote_build = GetRemoteBuildPath(revision, build_arch)
+    # Downloaded archive file path.
+    downloaded_file = os.path.join(
+        abs_build_dir,
+        GetZipFileName(revision, self.opts.target_arch, patch_sha))
+
     fetch_build_func = lambda: FetchFromCloudStorage(self.opts.gs_bucket,
-                                                     remote_build,
+                                                     source_file,
                                                      abs_build_dir)
+
     if not fetch_build_func():
-      if not self.PostBuildRequestAndWait(revision, condition=fetch_build_func):
+      if not self.PostBuildRequestAndWait(revision,
+                                          condition=fetch_build_func,
+                                          patch=patch):
         raise RuntimeError('Somewthing went wrong while processing build'
                            'request for: %s' % revision)
-
     # Generic name for the archive, created when archive file is extracted.
-    output_dir = os.path.join(abs_build_dir,
-                              GetZipFileName(target_arch=build_arch))
+    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)
-      ExtractZip(archive_file_dest, abs_build_dir)
+      ExtractZip(downloaded_file, abs_build_dir)
       if os.path.exists(output_dir):
         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)
         print 'Moving build from %s to %s' % (
             output_dir, target_build_output_dir)
         shutil.move(output_dir, target_build_output_dir)
         return True
       raise IOError('Missing extracted folder %s ' % output_dir)
-    except e:
+    except Exception as e:
       print 'Somewthing went wrong while extracting archive file: %s' % e
       self.BackupOrRestoreOutputdirectory(restore=True)
       # Cleanup any leftovers from unzipping.
@@ -1383,23 +1452,25 @@ class BisectPerformanceMetrics(object):
         RmTreeAndMkDir(output_dir, skip_makedir=True)
     finally:
       # Delete downloaded archive
-      if os.path.exists(archive_file_dest):
-        os.remove(archive_file_dest)
+      if os.path.exists(downloaded_file):
+        os.remove(downloaded_file)
     return False
 
   def PostBuildRequestAndWait(self, revision, condition, patch=None):
     """POSTs the build request job to the tryserver instance."""
 
     def GetBuilderNameAndBuildTime(target_arch='ia32'):
-      """Gets builder name and buildtime in seconds based on platform."""
+      """Gets builder bot name and buildtime in seconds based on platform."""
+      # Bot names should match the one listed in tryserver.chromium's
+      # master.cfg which produces builds for bisect.
       if IsWindows():
         if Is64BitWindows() and target_arch == 'x64':
-          return ('Win x64 Bisect Builder', 3600)
-        return ('Win Bisect Builder', 3600)
+          return ('win_perf_bisect_builder', MAX_WIN_BUILD_TIME)
+        return ('win_perf_bisect_builder', MAX_WIN_BUILD_TIME)
       if IsLinux():
-        return ('Linux Bisect Builder', 1800)
+        return ('linux_perf_bisect_builder', MAX_LINUX_BUILD_TIME)
       if IsMac():
-        return ('Mac Bisect Builder', 2700)
+        return ('mac_perf_bisect_builder', MAX_MAC_BUILD_TIME)
       raise NotImplementedError('Unsupported Platform "%s".' % sys.platform)
     if not condition:
       return False
@@ -1409,7 +1480,7 @@ class BisectPerformanceMetrics(object):
     # Creates a try job description.
     job_args = {'host': self.opts.builder_host,
                 'port': self.opts.builder_port,
-                'revision': revision,
+                'revision': 'src@%s' % revision,
                 'bot': bot_name,
                 'name': 'Bisect Job-%s' % revision
                }
@@ -1433,6 +1504,184 @@ class BisectPerformanceMetrics(object):
         time.sleep(poll_interval)
     return False
 
+  def IsDownloadable(self, depot):
+    """Checks if we can download builds for the depot from cloud."""
+    return (depot == 'chromium' or 'chromium' in DEPOT_DEPS_NAME[depot]['from']
+        or 'v8' in DEPOT_DEPS_NAME[depot]['from'])
+
+  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 to Angle repository because, in 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 self.UpdateDEPSForAngle(revision, depot, deps_file)
+
+    try:
+      deps_contents = ReadStringFromFile(deps_file)
+      # 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_var,
+                                 re.MULTILINE)
+      match = re.search(deps_revision, deps_contents)
+      if match:
+        svn_revision = self.source_control.SVNFindRev(
+            revision, self._GetDepotDirectory(depot))
+        if not svn_revision:
+          print 'Could not determine SVN revision for %s' % revision
+          return False
+        # Update the revision information for the given depot
+        new_data = re.sub(deps_revision, str(svn_revision), deps_contents)
+
+        # For v8_bleeding_edge revisions change V8 branch in order
+        # to fetch bleeding edge revision.
+        if depot == 'v8_bleeding_edge':
+          new_data = self.UpdateV8Branch(new_data)
+          if not new_data:
+            return False
+        # 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 UpdateV8Branch(self, 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(self, 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 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).
+    chromium_sha = CheckRunGit(['rev-parse', 'HEAD']).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 = 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.
 
@@ -1445,15 +1694,24 @@ class BisectPerformanceMetrics(object):
     os.chdir(self.src_cwd)
     # Fetch build archive for the given revision from the cloud storage when
     # the storage bucket is passed.
-    if depot == 'chromium' and self.opts.gs_bucket and revision:
+    if self.IsDownloadable(depot) and self.opts.gs_bucket 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)
       # Get SVN revision for the given SHA, since builds are archived using SVN
       # revision.
-      revision = self.source_control.SVNFindRev(revision)
-      if not revision:
+      chromium_revision = self.source_control.SVNFindRev(revision)
+      if not chromium_revision:
         raise RuntimeError(
-            'Failed to determine SVN revision for %s' % sha_revision)
-      if self.DownloadCurrentBuild(revision):
+            'Failed to determine SVN revision for %s' % revision)
+      if self.DownloadCurrentBuild(chromium_revision, patch=deps_patch):
         os.chdir(cwd)
+        if deps_patch:
+          # Reverts the changes to DEPS file.
+          self.source_control.CheckoutFileAtRevision(bisect_utils.FILE_DEPS,
+                                                     revision,
+                                                     cwd=self.src_cwd)
         return True
       raise RuntimeError('Failed to download build archive for revision %s.\n'
                          'Unfortunately, bisection couldn\'t continue any '
@@ -1769,7 +2027,7 @@ class BisectPerformanceMetrics(object):
 
     # Having these pyc files around between runs can confuse the
     # perf tests and cause them to crash.
-    for (path, dir, files) in os.walk(self.src_cwd):
+    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)
@@ -1999,8 +2257,7 @@ class BisectPerformanceMetrics(object):
       return self.depot_cwd[depot_name]
     else:
       assert False, 'Unknown depot [ %s ] encountered. Possibly a new one'\
-                    ' was added without proper support?' %\
-                    (depot_name,)
+                    ' was added without proper support?' % depot_name
 
   def ChangeToDepotWorkingDirectory(self, depot_name):
     """Given a depot, changes to the appropriate working directory.
@@ -2167,7 +2424,7 @@ class BisectPerformanceMetrics(object):
 
     num_depot_revisions = len(revisions)
 
-    for k, v in revision_data.iteritems():
+    for _, v in revision_data.iteritems():
       if v['sort'] > sort:
         v['sort'] += num_depot_revisions
 
@@ -2490,7 +2747,7 @@ class BisectPerformanceMetrics(object):
 
             if not new_revision_list:
               results['error'] = 'An error occurred attempting to retrieve'\
-                                 ' revision range: [%s..%s]' %\
+                                 ' revision range: [%s..%s]' % \
                                  (earliest_revision, latest_revision)
               return results
 
@@ -2582,8 +2839,6 @@ class BisectPerformanceMetrics(object):
     revision_data_sorted = sorted(revision_data.iteritems(),
                                   key = lambda x: x[1]['sort'])
     results_dict = self._GetResultsDict(revision_data, revision_data_sorted)
-    first_working_revision = results_dict['first_working_revision']
-    last_broken_revision = results_dict['last_broken_revision']
 
     self._PrintTestedCommitsTable(revision_data_sorted,
                                   results_dict['first_working_revision'],
@@ -3015,7 +3270,7 @@ def DetermineAndCreateSourceControl(opts):
     is unsupported.
   """
 
-  (output, return_code) = RunGit(['rev-parse', '--is-inside-work-tree'])
+  (output, _) = RunGit(['rev-parse', '--is-inside-work-tree'])
 
   if output.strip() == 'true':
     return GitSourceControl(opts)
@@ -3238,7 +3493,7 @@ class BisectOptions(object):
   def ParseCommandLine(self):
     """Parses the command line for bisect options."""
     parser = self._CreateCommandLineParser()
-    (opts, args) = parser.parse_args()
+    (opts, _) = parser.parse_args()
 
     try:
       if not opts.command:
@@ -3331,7 +3586,7 @@ def main():
 
   try:
     opts = BisectOptions()
-    parse_results = opts.ParseCommandLine()
+    opts.ParseCommandLine()
 
     if opts.extra_src:
       extra_src = bisect_utils.LoadExtraSrc(opts.extra_src)