Add more logging when fetching layout test results.

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl.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 fetch new baselines from try jobs for the current CL."""
 
 import json
 import logging
 import optparse
 
@@ skipping 136 matching lines @@
         Returns:
             A dict mapping Build to LayoutTestResults, or None if any results
             were not available.
         """
         buildbot = self._tool.buildbot
         results = {}
         for build in builds:
             results_url = buildbot.results_url(build.builder_name, build.build_number)
             layout_test_results = buildbot.fetch_results(build)
             if layout_test_results is None:
-                _log.error(
-                    'Failed to fetch results from "%s".\n'
-                    'Try starting a new job for %s by running :\n'
-                    '  git cl try -b %s',
-                    results_url, build.builder_name, build.builder_name)
+                _log.error('Failed to fetch results for: %s', build)
+                _log.error('Results were expected to exist at:\n%s/results.html', results_url)
+                _log.error('If the job failed, you could retry by running:\ngit cl try -b %s', build.builder_name)
                 return None
             results[build] = layout_test_results
         return results
 
     def _test_prefix_list(self, builds_to_results, only_changed_tests):
         """Returns a dict which lists the set of baselines to fetch.
 
         The dict that is returned is a dict of tests to Build objects
         to baseline file extensions.
 
@@ skipping 56 matching lines @@
     def _log_test_prefix_list(test_prefix_list):
         """Logs the tests to download new baselines for."""
         if not test_prefix_list:
             _log.info('No tests to rebaseline; exiting.')
             return
         _log.debug('Tests to rebaseline:')
         for test, builds in test_prefix_list.iteritems():
             _log.debug('  %s:', test)
             for build in sorted(builds):
                 _log.debug('    %s', build)