Revert of Remove default begin frame sources from the renderer

cc/trees/layer_tree_settings.h

 // Copyright 2011 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.
 
 #ifndef CC_TREES_LAYER_TREE_SETTINGS_H_
 #define CC_TREES_LAYER_TREE_SETTINGS_H_
 
 #include <stddef.h>
 
 #include <vector>
@@ skipping 23 matching lines @@
   void ToProtobuf(proto::LayerTreeSettings* proto) const;
   void FromProtobuf(const proto::LayerTreeSettings& proto);
 
   SchedulerSettings ToSchedulerSettings() const;
 
   RendererSettings renderer_settings;
   bool single_thread_proxy_scheduler = true;
   // TODO(enne): Remove this after everything uses output surface begin frames.
   bool use_external_begin_frame_source = false;
   // TODO(enne): Temporary staging for unified begin frame source work.
-  bool use_output_surface_begin_frame_source = true;
+  bool use_output_surface_begin_frame_source = false;
   bool main_frame_before_activation_enabled = false;
   bool using_synchronous_renderer_compositor = false;
   bool can_use_lcd_text = true;
   bool use_distance_field_text = false;
   bool gpu_rasterization_enabled = false;
   bool gpu_rasterization_forced = false;
   bool async_worker_context_enabled = false;
   int gpu_rasterization_msaa_sample_count = 0;
   float gpu_rasterization_skewport_target_time_in_seconds = 0.2f;
   bool create_low_res_tiling = false;
@@ skipping 48 matching lines @@
   // If set to true, the display item list will internally cache a SkPicture for
   // raster rather than directly using the display items.
   bool use_cached_picture_raster = true;
 
   LayerTreeDebugState initial_debug_state;
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_SETTINGS_H_