sync compositor: Reduce begin frame sync IPC overhead

content/content_browser.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_static',
     '../cc/cc.gyp:cc',
     '../cc/cc.gyp:cc_surfaces',
     '../components/components.gyp:display_compositor',
@@ skipping 1657 matching lines @@
       'browser/android/java/jni_helper.cc',
       'browser/android/java/jni_helper.h',
       'browser/android/load_url_params.cc',
       'browser/android/load_url_params.h',
       'browser/android/overscroll_controller_android.cc',
       'browser/android/overscroll_controller_android.h',
       'browser/android/popup_touch_handle_drawable.cc',
       'browser/android/popup_touch_handle_drawable.h',
       'browser/android/synchronous_compositor_host.cc',
       'browser/android/synchronous_compositor_host.h',
+      'browser/android/synchronous_compositor_observer.cc',
+      'browser/android/synchronous_compositor_observer.h',
       'browser/android/tracing_controller_android.cc',
       'browser/android/tracing_controller_android.h',
       'browser/android/web_contents_observer_proxy.cc',
       'browser/android/web_contents_observer_proxy.h',
       'browser/media/capture/screen_capture_device_android.cc',
       'browser/media/capture/screen_capture_device_android.h',
       'browser/renderer_host/compositor_impl_android.cc',
       'browser/renderer_host/compositor_impl_android.h',
       'browser/renderer_host/ime_adapter_android.cc',
       'browser/renderer_host/ime_adapter_android.h',
@@ skipping 486 matching lines @@
       ],
     }],
     ['OS != "mac" and OS != "android"', {
       'sources!': [
         'browser/gpu/gpu_surface_tracker.cc',
         'browser/gpu/gpu_surface_tracker.h',
       ],
     }],
   ],
 }