Remove external begin frame source parameter and settings

ui/compositor/compositor.cc

 // 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.
 
 #include "ui/compositor/compositor.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <deque>
@@ skipping 165 matching lines @@
       settings.renderer_settings.buffer_to_texture_target_map.insert(
           cc::BufferToTextureTargetMap::value_type(
               cc::BufferToTextureTargetKey(usage, format), target));
     }
   }
 
   // Note: Only enable image decode tasks if we have more than one worker
   // thread.
   settings.image_decode_tasks_enabled = false;
 
-  settings.use_compositor_frame_sink_begin_frame_source = true;
-
   settings.gpu_memory_policy.bytes_limit_when_visible = 512 * 1024 * 1024;
   settings.gpu_memory_policy.priority_cutoff_when_visible =
       gpu::MemoryAllocation::CUTOFF_ALLOW_NICE_TO_HAVE;
 
   base::TimeTicks before_create = base::TimeTicks::Now();
 
   cc::LayerTreeHostInProcess::InitParams params;
   params.client = this;
   params.shared_bitmap_manager = context_factory_->GetSharedBitmapManager();
   params.gpu_memory_buffer_manager =
@@ skipping 352 matching lines @@
                     observer_list_,
                     OnCompositingLockStateChanged(this));
 }
 
 void Compositor::CancelCompositorLock() {
   if (compositor_lock_)
     compositor_lock_->CancelLock();
 }
 
 }  // namespace ui