Move KillRing to platform/

Source/platform/blink_platform.gyp

 #
 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 95 matching lines @@
         'link_settings': {
           'libraries': [
             '$(SDKROOT)/System/Library/Frameworks/Accelerate.framework',
             '$(SDKROOT)/System/Library/Frameworks/Carbon.framework',
             '$(SDKROOT)/System/Library/Frameworks/Foundation.framework',
           ]
         },
         'sources/': [
           # We use LocaleMac.mm instead of LocaleICU.cpp
           ['exclude', 'LocaleICU\\.(cpp|h)$'],
+
+          # The Mac uses mac/KillRingMac.mm instead of the dummy
+          # implementation.
+          ['exclude', 'KillRingNone\\.cpp$'],
         ],
       }, { # OS!="mac"
         'sources/': [
           ['exclude', 'mac/'],
         ],
       }],
       ['OS=="win"', {
         'sources/': [
           # We use LocaleWin.cpp instead of LocaleICU.cpp
           ['exclude', 'LocaleICU\\.(cpp|h)$'],
@@ skipping 16 matching lines @@
          'include_dirs': [
            '<(DEPTH)/third_party/openmax_dl',
          ],
         'dependencies': [
           '<(DEPTH)/third_party/openmax_dl/dl/dl.gyp:openmax_dl',
         ],
       }],
     ],
   }],
 }