Move Mailbox from cc to gpu, and its traits to gpu/ipc

cc/cc.gyp

 # 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.
 
 {
   'variables': {
     'cc_source_files': [
       'animation.cc',
       'animation.h',
       'animation_curve.cc',
@@ skipping 325 matching lines @@
       ],
     }],
   ],
   'targets': [
     {
       'target_name': 'cc',
       'type': '<(component)',
       'dependencies': [
         '<(DEPTH)/base/base.gyp:base',
         '<(DEPTH)/base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
+        '<(DEPTH)/gpu/gpu.gyp:gpu',
         '<(DEPTH)/skia/skia.gyp:skia',
         '<(DEPTH)/media/media.gyp:media',
         '<(DEPTH)/ui/gl/gl.gyp:gl',
         '<(DEPTH)/ui/ui.gyp:ui',
         '<(webkit_src_dir)/Source/WebKit/chromium/WebKit.gyp:webkit',
       ],
       'defines': [
         'CC_IMPLEMENTATION=1',
       ],
       'sources': [
         '<@(cc_source_files)',
       ],
       # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
       'msvs_disabled_warnings': [ 4267, ],
     },
   ],
 }