message: Fix chromium autoroller to parse new clang revision format
  Cr-Commit-Position: refs/heads/master@{#28042}
diff: @@ -56,7 +56,7 @@ CHROMIUM_LOG_TEMPLATE = CHROMIUM_SRC_URL + '/+log/%s'
  CHROMIUM_FILE_TEMPLATE = CHROMIUM_SRC_URL + '/+/%s/%s'
  COMMIT_POSITION_RE = re.compile('^Cr-Commit-Position: .*#([0-9]+).*$')
  -CLANG_REVISION_RE = re.compile(r'^CLANG_REVISION = \'(\d+)\'$')
  +CLANG_REVISION_RE = re.compile(r'^CLANG_REVISION = \'([0-9a-z]+)\'$')
  ROLL_BRANCH_NAME = 'roll_chromium_revision'
  SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
  