on CompareGMs failure, show link to most recent results on this builder

slave/skia_slave_scripts/compare_gms.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """ Compare the generated GM images to the baselines """
 
 # System-level imports
 import os
 import sys
 
 from build_step import BuildStep, BuildStepWarning
 from utils import misc
 import run_gm
 
+LIVE_REBASELINE_SERVER_BASEURL = (
+    'http://skia-tree-status.appspot.com/redirect/rebaseline-server/'
+    'static/view.html#/view.html')
+# EPOGER: how can I share this definition with factory.py?
+LATEST_GM_FAILURES_PREAMBLE = 'View latest GM failures for this builder at: '
+
 class CompareGMs(BuildStep):
   def _Run(self):
     json_summary_path = misc.GetAbsPath(os.path.join(
         self._gm_actual_dir, run_gm.JSON_SUMMARY_FILENAME))
 
     # Temporary list of builders who are allowed to fail this step without the
     # bot turning red.
     may_fail_with_warning = []
     # This import must happen after BuildStep.__init__ because it requires that
     # CWD is in PYTHONPATH, and BuildStep.__init__ may change the CWD.
     from gm import display_json_results
-    if not display_json_results.Display(json_summary_path):
+    success = display_json_results.Display(json_summary_path)
+    print '%s%s?resultsToLoad=/results/failures&builder=%s' % (
+        LATEST_GM_FAILURES_PREAMBLE, LIVE_REBASELINE_SERVER_BASEURL,
+        self._builder_name)
+    if not success:
       if self._builder_name in may_fail_with_warning:
         raise BuildStepWarning('Expectations mismatch in %s!' %
                                json_summary_path)
       else:
         raise Exception('Expectations mismatch in %s!' % json_summary_path)
 
 
 if '__main__' == __name__:
   sys.exit(BuildStep.RunBuildStep(CompareGMs))