Fix git log command to while processing Commit position in SVNFindRev method

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
 import re
 
 from . import bisect_utils
@@ skipping 212 matching lines @@
     output = bisect_utils.CheckRunGit(cmd, cwd)
     svn_revision = output.strip()
 
     if bisect_utils.IsStringInt(svn_revision):
       return int(svn_revision)
 
     # Retrieve commit position number from git log body for the given revision.
     # TODO(prasadv): Use an appropriate command to find commit position instead
     # of parsing the log. Resolve this once 407316 is fixed.
     commit_position_pattern = 'Cr-Commit-Position: .*@\{#(?P<commit>[0-9]+)\}'
-    cmd = ['log', '--format=%b', '-1', 'origin/master', git_revision]
+    cmd = ['log', '--format=%b', '-1', git_revision]
     output = bisect_utils.CheckRunGit(cmd, cwd=cwd)
     if output:
       version_re = re.compile(commit_position_pattern)
       commit_reg = version_re.search(output)
       if commit_reg and bisect_utils.IsStringInt(commit_reg.group('commit')):
         return int(commit_reg.group('commit'))
 
     return None
 
   def QueryRevisionInfo(self, revision, cwd=None):
@@ skipping 54 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]