Add presubmit warning about deprecated compiled_resources.gyp

PRESUBMIT_test_mocks.py

 # Copyright 2014 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 json
 import os
 import re
 import subprocess
 import sys
 
@@ skipping 79 matching lines @@
 
   This class can be used to form the mock list of changed files in
   MockInputApi for presubmit unittests.
   """
 
   def __init__(self, local_path, new_contents):
     self._local_path = local_path
     self._new_contents = new_contents
     self._changed_contents = [(i + 1, l) for i, l in enumerate(new_contents)]
 
+  def Action(self):
+    return 'A'  # TODO(dbeam): feel free to change if your test actually uses.
+
   def ChangedContents(self):
     return self._changed_contents
 
   def NewContents(self):
     return self._new_contents
 
   def LocalPath(self):
     return self._local_path
 
   def rfind(self, p):
@@ skipping 15 matching lines @@
 
   This class can be used in presubmit unittests to mock the query of the
   current change.
   """
 
   def __init__(self, changed_files):
     self._changed_files = changed_files
 
   def LocalPaths(self):
     return self._changed_files