Remove the --disable-begin-frame-scheduling flag

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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 "content/renderer/gpu/render_widget_compositor.h"
 
 #include <stddef.h>
 #include <limits>
 #include <string>
 #include <utility>
@@ skipping 457 matching lines @@
     settings.gpu_decoded_image_budget_bytes = 96 * 1024 * 1024;
     settings.software_decoded_image_budget_bytes = 128 * 1024 * 1024;
   }
 
 #endif  // defined(OS_ANDROID)
 
   if (cmd.HasSwitch(switches::kEnableLowResTiling))
     settings.create_low_res_tiling = true;
   if (cmd.HasSwitch(switches::kDisableLowResTiling))
     settings.create_low_res_tiling = false;
-  if (!cmd.HasSwitch(cc::switches::kDisableBeginFrameScheduling))
-    settings.use_external_begin_frame_source = true;
+  settings.use_external_begin_frame_source = true;
 
   if (cmd.HasSwitch(switches::kEnableRGBA4444Textures) &&
       !cmd.HasSwitch(switches::kDisableRGBA4444Textures)) {
     settings.renderer_settings.preferred_tile_format = cc::RGBA_4444;
   }
 
   if (cmd.HasSwitch(cc::switches::kEnableTileCompression)) {
     settings.renderer_settings.preferred_tile_format = cc::ETC1;
   }
 
@@ skipping 648 matching lines @@
 
   remote_proto_channel_receiver_->OnProtoReceived(std::move(deserialized));
 }
 
 void RenderWidgetCompositor::SetPaintedDeviceScaleFactor(
     float device_scale) {
   layer_tree_host_->GetLayerTree()->SetPaintedDeviceScaleFactor(device_scale);
 }
 
 }  // namespace content