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

master/skia_master_scripts/factory.py

 # Copyright (c) 2013 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.
 
 
 """Utility class to build the Skia master BuildFactory's.
 
 Based on gclient_factory.py and adds Skia-specific steps."""
 
 
 from buildbot.process.properties import WithProperties
 from buildbot.status import builder
 from config_private import AUTOGEN_SVN_BASEURL, SKIA_GIT_URL
 from master.factory import gclient_factory
 from master.factory.build_factory import BuildFactory
 from skia_master_scripts import commands as skia_commands
 
 import builder_name_schema
 import config
 import config_private
 import ntpath
 import os
 import posixpath
+import skia_vars
 import utils
 
 
 # TODO(epoger): My intent is to make the build steps identical on all platforms
 # and thus remove the need for the whole target_platform parameter.
 # For now, these must match the target_platform values used in
 # third_party/chromium_buildbot/scripts/master/factory/gclient_factory.py ,
 # because we pass these values into GClientFactory.__init__() .
 TARGET_PLATFORM_LINUX = 'linux'
 TARGET_PLATFORM_MAC = 'mac'
@@ skipping 490 matching lines @@
   def PostBench(self):
     """ Step to run after the benchmarking steps. """
     self.AddFlavoredSlaveScript(script='postbench.py',
                                 description='PostBench',
                                 exception_on_failure=True)
 
   def CompareGMs(self):
     """Compare the actually-generated GM images to the checked-in baselines."""
     self.AddSlaveScript(script='compare_gms.py',
                         description='CompareGMs',
+                        get_props_from_stdout={
+                            'latest_gm_failures_url':
+                            '%s([^\n]*)\n' % skia_vars.GetGlobalVariable(
+                                'latest_gm_failures_preamble')},
                         is_rebaseline_step=True)
 
   def CompareRenderedSKPs(self):
     """Compare the actual image results of SKP rendering to expectations."""
     self.AddSlaveScript(script='compare_rendered_skps.py',
                         description='CompareRenderedSKPs',
                         is_rebaseline_step=True)
 
   def RunBench(self):
     """ Run "bench", piping the output somewhere so we can graph
@@ skipping 263 matching lines @@
         # Perf-only builder.
         if not self._perf_output_basedir:
           raise ValueError(
               'BuildPerfOnly requires perf_output_basedir to be defined.')
         if self._configuration != CONFIG_RELEASE:
           raise ValueError('BuildPerfOnly should run in %s configuration.' %
                            CONFIG_RELEASE)
         self.PerfSteps()
     self.Validate()
     return self