Teach bisect script to resolve Cr-Commit-Positions.

tools/auto_bisect/source_control.py

 # Copyright 2014 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 module contains the SourceControl class and related functions."""
 
 import os
 
 from . import bisect_utils
 
@@ skipping 96 matching lines @@
       results = bisect_utils.RunGit(['checkout', revision])[1]
     elif sync_client == 'gclient':
       results = self.SyncToRevisionWithGClient(revision)
     elif sync_client == 'repo':
       results = self.SyncToRevisionWithRepo(revision)
 
     return not results
 
   def ResolveToRevision(self, revision_to_check, depot, depot_deps_dict,
                         search, cwd=None):
-    """If an SVN revision is supplied, try to resolve it to a git SHA1.
+    """Tries to resolve an SVN revision or commit position to a git SHA1.
 
     Args:
       revision_to_check: The user supplied revision string that may need to be
         resolved to a git SHA1.
       depot: The depot the revision_to_check is from.
       depot_deps_dict: A dictionary with information about different depots.
       search: The number of changelists to try if the first fails to resolve
         to a git hash. If the value is negative, the function will search
         backwards chronologically, otherwise it will search forward.
 
@@ skipping 16 matching lines @@
       svn_revision = int(revision_to_check)
       git_revision = None
 
       if search > 0:
         search_range = xrange(svn_revision, svn_revision + search, 1)
       else:
         search_range = xrange(svn_revision, svn_revision + search, -1)
 
       for i in search_range:
         svn_pattern = 'git-svn-id: %s@%d' % (depot_svn, i)
+        commit_position_pattern = 'Cr-Commit-Position: .*@{#%d}' % i
         cmd = ['log', '--format=%H', '-1', '--grep', svn_pattern,
-               'origin/master']
+               '--grep', commit_position_pattern, 'origin/master']
 
         (log_output, return_code) = bisect_utils.RunGit(cmd, cwd=cwd)
 
         assert not return_code, 'An error occurred while running'\
                                 ' "git %s"' % ' '.join(cmd)
 
         if not return_code:
           log_output = log_output.strip()
 
           if log_output:
@@ skipping 113 matching lines @@
         revision_end: End of revision range.
 
     Returns:
         Returns a list of commits that touched this file.
     """
     cmd = ['log', '--format=%H', '%s~1..%s' % (revision_start, revision_end),
            filename]
     output = bisect_utils.CheckRunGit(cmd)
 
     return [o for o in output.split('\n') if o]