android: Make proguard .flags file more diff-friendly

build/android/gyp/util/proguard_util.py

 # Copyright 2015 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 os
 import re
 import time
 from util import build_utils
 
 
@@ skipping 145 matching lines @@
     if self._mapping:
       inputs.append(self._mapping)
     if self._libraries:
       inputs += self._libraries
     if self._tested_apk_info_path:
       inputs += [self._tested_apk_info_path]
     return inputs
 
   def _WriteFlagsFile(self, out):
     # Quite useful for auditing proguard flags.
-    for config in self._configs:
+    for config in sorted(self._configs):
       out.write('#' * 80 + '\n')
       out.write(config + '\n')
       out.write('#' * 80 + '\n')
       with open(config) as config_file:
-        out.write(config_file.read().rstrip())
+        contents = config_file.read().rstrip()
+      # Remove numbers from generated rule comments to make file more
+      # diff'able.
+      contents = re.sub(r' #generated:\d+', '', contents)
+      out.write(contents)
       out.write('\n\n')
     out.write('#' * 80 + '\n')
     out.write('Command-line\n')
     out.write('#' * 80 + '\n')
     out.write(' '.join(self._cmd) + '\n')
 
   def CheckOutput(self):
     self.build()
     # Proguard will skip writing these files if they would be empty. Create
     # empty versions of them all now so that they are updated as the build
@@ skipping 19 matching lines @@
                             stderr_filter=stderr_filter)
 
     this_info = {
       'inputs': self._injars,
       'configs': self._configs,
       'mapping': self._outjar + '.mapping',
       'elapsed_time': round(time.time() - start_time),
     }
 
     build_utils.WriteJson(this_info, self._outjar + '.info')