Add CopyOnWriteBuffer class

webrtc/base/base.gyp

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 {
   'includes': [ '../build/common.gypi', ],
@@ skipping 175 matching lines @@
         'autodetectproxy.cc',
         'autodetectproxy.h',
         'bandwidthsmoother.cc',
         'bandwidthsmoother.h',
         'base64.cc',
         'base64.h',
         'bind.h',
         'callback.h',
         'common.cc',
         'common.h',
+        'copyonwritebuffer.cc',
+        'copyonwritebuffer.h',
         'crc32.cc',
         'crc32.h',
         'cryptstring.cc',
         'cryptstring.h',
         'dbus.cc',
         'dbus.h',
         'diskcache.cc',
         'diskcache.h',
         'diskcache_win32.cc',
         'diskcache_win32.h',
@@ skipping 542 matching lines @@
     },
     {
      'target_name': 'gtest_prod',
       'type': 'static_library',
       'sources': [
         'gtest_prod_util.h',
       ],
     },
   ],
 }