Add build link to rebaseline-o-matic CL descriptions.

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/auto_rebaseline.py

 # Copyright 2016 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.
 
 """A command to download new baselines for NeedsRebaseline tests.
 
 This command checks the list of tests with NeedsRebaseline expectations,
 and downloads the latest baselines for those tests from the results archived
 by the continuous builders.
 """
 
 import logging
 import optparse
 import re
 import sys
 import time
 import traceback
 import urllib2
 
-from webkitpy.common.net.buildbot import Build
+from webkitpy.common.net.buildbot import Build, current_build_link
 from webkitpy.layout_tests.models.test_expectations import TestExpectations, BASELINE_SUFFIX_LIST
 from webkitpy.tool.commands.rebaseline import AbstractParallelRebaselineCommand
 
 
 _log = logging.getLogger(__name__)
 
 
 class AutoRebaseline(AbstractParallelRebaselineCommand):
     name = "auto-rebaseline"
     help_text = "Rebaselines any NeedsRebaseline lines in TestExpectations that have cycled through all the bots."
@@ skipping 97 matching lines @@
 
             bugs.update(re.findall(r"crbug\.com\/(\d+)", line))
             tests.add(test)
 
             if len(tests) >= self.MAX_LINES_TO_REBASELINE:
                 _log.info("Too many tests to rebaseline in one patch. Doing the first %d.", self.MAX_LINES_TO_REBASELINE)
                 break
 
         return tests, revision, commit, author, bugs, has_any_needs_rebaseline_lines
 
+    def commit_message(self, author, revision, commit, bugs):
+        message = 'Auto-rebaseline for r%s\n\n' % revision
+        build_link = current_build_link(self._tool)
+        if build_link:
+            message += 'Build: %s\n\n' % build_link
+        message += '%s\n\n' % self.link_to_patch(commit)
+        if bugs:
+            message += 'BUG=%s\n' % ','.join(bugs)
+        message += 'TBR=%s\n' % author
+        return message
+
     @staticmethod
     def link_to_patch(commit):
-        return "https://chromium.googlesource.com/chromium/src/+/" + commit
-
-    def commit_message(self, author, revision, commit, bugs):
-        bug_string = ""
-        if bugs:
-            bug_string = "BUG=%s\n" % ",".join(bugs)
-
-        return """Auto-rebaseline for r%s
-
-%s
-
-%sTBR=%s
-""" % (revision, self.link_to_patch(commit), bug_string, author)
+        return 'https://chromium.googlesource.com/chromium/src/+/' + commit
 
     def get_test_prefix_list(self, tests):
         test_prefix_list = {}
         lines_to_remove = {}
 
         for builder_name in self._release_builders():
             port_name = self._tool.builders.port_name_for_builder_name(builder_name)
             port = self._tool.port_factory.get(port_name)
             expectations = TestExpectations(port, include_overrides=True)
             for test in expectations.get_needs_rebaseline_failures():
@@ skipping 126 matching lines @@
                     issue_already_closed = tool.executive.run_command(
                         ['git', 'config', 'branch.%s.rietveldissue' % rebaseline_branch_name],
                         return_exit_code=True)
                     if not issue_already_closed:
                         self._run_git_cl_command(options, ['set_close'])
 
                 tool.scm().ensure_cleanly_tracking_remote_master()
                 if old_branch_name_or_ref:
                     tool.scm().checkout_branch(old_branch_name_or_ref)
                 tool.scm().delete_branch(rebaseline_branch_name)