V8: Fix gyp flag comparison for windows.

scripts/slave/recipe_modules/v8/api.py

 # Copyright 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.
 
 import argparse
 import datetime
 import difflib
 import random
 import re
 import urllib
@@ skipping 414 matching lines @@
           # No '=' in x. It's part of a quoted string containing a space.
           # Append it to the last value.
           result[-1][1] += (' ' + kv[0])
         else:
           result.append(kv)
       return dict(tuple(kv) for kv in result)
 
     infra_flags = gyp_defines_to_dict(
         self.m.chromium.c.gyp_env.as_jsonish()['GYP_DEFINES'])
 
-    # Get the client's gyp flags from MB's output.
-    match = re.search('^GYP_DEFINES=\'(.*)\'$', mb_output, re.M)
+    # Get the client's gyp flags from MB's output. Group 1 captures with posix,
+    # group 2 with windows output semantics.
+    #
+    # Posix:
+    # GYP_DEFINES='foo=1 path=a/b/c'
+    #
+    # Windows:
+    # set GYP_DEFINES=foo=1 path='a/b/c'
+    match = re.search(
+        '^(?:set )?GYP_DEFINES=(?:(?:\'(.*)\')|(?:(.*)))$', mb_output, re.M)
 
     # This won't match in the gn case.
     if match:
-      client_flags = gyp_defines_to_dict(match.group(1))
+      client_flags = gyp_defines_to_dict(match.group(1) or match.group(2))
 
       # Tweak both dictionaries for known differences.
       if infra_flags.get('target_arch') == infra_flags.get('v8_target_arch'):
         # We drop the default case target_arch==v8_target_arch in MB and
         # only specify target_arch.
         infra_flags.pop('v8_target_arch')  # pragma: no cover
 
       if 'jsfunfuzz' in infra_flags:
         # This is for runhooks only. Not used in MB.
         infra_flags.pop('jsfunfuzz')  # pragma: no cover
@@ skipping 804 matching lines @@
   def report_culprits(self, culprit_range):
     assert culprit_range
     if len(culprit_range) > 1:
       text = 'Suspecting multiple commits'
     else:
       text = 'Suspecting %s' % culprit_range[0][:8]
 
     step_result = self.m.step(text, cmd=None)
     for culprit in culprit_range:
       step_result.presentation.links[culprit[:8]] = COMMIT_TEMPLATE % culprit