Add embedder api for participating in gpu logic

content/content_gpu.gypi

 # 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base',
     '../skia/skia.gyp:skia',
     '../ui/gl/gl.gyp:gl',
     'content_common_mojo_bindings.gyp:content_common_mojo_bindings',
   ],
   'sources': [
     'gpu/gpu_child_thread.cc',
     'gpu/gpu_child_thread.h',
     'gpu/gpu_main.cc',
     'gpu/gpu_process.cc',
     'gpu/gpu_process.h',
     'gpu/gpu_process_control_impl.cc',
     'gpu/gpu_process_control_impl.h',
     'gpu/gpu_watchdog_thread.cc',
     'gpu/gpu_watchdog_thread.h',
     'gpu/in_process_gpu_thread.cc',
     'gpu/in_process_gpu_thread.h',
+    'public/gpu/content_gpu_client.h',
   ],
   'include_dirs': [
     '..',
   ],
   'conditions': [
     ['OS=="win"', {
       'include_dirs': [
         '<(DEPTH)/third_party/khronos',
         # ANGLE libs picked up from ui/gl
         '<(angle_path)/src',
         '<(DEPTH)/third_party/wtl/include',
       ],
       'link_settings': {
         'libraries': [
           '-lsetupapi.lib',
         ],
       },
     }],
     ['target_arch!="arm" and chromeos == 1', {
       'include_dirs': [
         '<(DEPTH)/third_party/libva',
       ],
     }],
   ],
 }