Simplify rate limiting since it's main thread shared context only

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': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 360 matching lines @@
         'resources/ui_resource_bitmap.h',
         'resources/ui_resource_client.h',
         'resources/video_resource_updater.cc',
         'resources/video_resource_updater.h',
         'resources/worker_pool.cc',
         'resources/worker_pool.h',
         'scheduler/delay_based_time_source.cc',
         'scheduler/delay_based_time_source.h',
         'scheduler/frame_rate_controller.cc',
         'scheduler/frame_rate_controller.h',
-        'scheduler/rate_limiter.cc',
-        'scheduler/rate_limiter.h',
         'scheduler/rolling_time_delta_history.cc',
         'scheduler/rolling_time_delta_history.h',
         'scheduler/scheduler.cc',
         'scheduler/scheduler.h',
         'scheduler/scheduler_settings.cc',
         'scheduler/scheduler_settings.h',
         'scheduler/scheduler_state_machine.cc',
         'scheduler/scheduler_state_machine.h',
         'scheduler/texture_uploader.cc',
         'scheduler/texture_uploader.h',
@@ skipping 26 matching lines @@
         'trees/thread_proxy.cc',
         'trees/thread_proxy.h',
         'trees/tree_synchronizer.cc',
         'trees/tree_synchronizer.h',
       ],
       # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
       'msvs_disabled_warnings': [ 4267, ],
     },
   ],
 }