Add chrome/plugin and chrome/utility to GN build.

webkit/common/gpu/webkit_gpu.gyp

 # Copyright (c) 2013 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.
 
 {
   'conditions': [
     # TODO(stuartmorgan): All dependencies from code built on iOS to
     # webkit/ should be removed, at which point this condition can be
     # removed.
     ['OS != "ios"', {
       'targets': [
         {
+          # GN version: //webkit/common/gpu
           'target_name': 'webkit_gpu',
           'type': '<(component)',
           'variables': { 'enable_wexit_time_destructors': 1, },
           'dependencies': [
             '<(DEPTH)/base/base.gyp:base',
             '<(DEPTH)/cc/cc.gyp:cc',
             '<(DEPTH)/base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
             '<(DEPTH)/gpu/command_buffer/command_buffer.gyp:gles2_utils',
             '<(DEPTH)/gpu/gpu.gyp:command_buffer_service',
             '<(DEPTH)/gpu/gpu.gyp:gles2_c_lib',
@@ skipping 22 matching lines @@
           'defines': [
             'WEBKIT_GPU_IMPLEMENTATION',
           ],
           # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
           'msvs_disabled_warnings': [ 4267, ],
         },
       ],
     }],
   ],
 }