[Mac] Move the large block of NSEvent forward declarations to a shared header.

base/PRESUBMIT.py

 # Copyright (c) 2012 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.
 
 """Chromium presubmit script for src/base.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details on the presubmit API built into gcl.
 """
 
 def _CheckNoInterfacesInBase(input_api, output_api):
   """Checks to make sure no files in libbase.a have |@interface|."""
   pattern = input_api.re.compile(r'^\s*@interface', input_api.re.MULTILINE)
   files = []
   for f in input_api.AffectedSourceFiles(input_api.FilterSourceFile):
     if (f.LocalPath().startswith('base/') and
         not "/test/" in f.LocalPath() and
-        not f.LocalPath().endswith('_unittest.mm')):
+        not f.LocalPath().endswith('_unittest.mm') and
+        not f.LocalPath().endswith('mac/sdk_forward_declarations.h')):
       contents = input_api.ReadFile(f)
       if pattern.search(contents):
         files.append(f)
 
   if len(files):
     return [ output_api.PresubmitError(
         'Objective-C interfaces or categories are forbidden in libbase. ' +
         'See http://groups.google.com/a/chromium.org/group/chromium-dev/' +
         'browse_thread/thread/efb28c10435987fd',
         files) ]
@@ skipping 17 matching lines @@
   results.extend(_CommonChecks(input_api, output_api))
   return results
 
 
 def GetPreferredTrySlaves():
   return [
     'linux_rel:sync_integration_tests',
     'mac_rel:sync_integration_tests',
     'win_rel:sync_integration_tests',
   ]