Revert of Remove default begin frame sources from the renderer

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 226 matching lines @@
   params.shared_bitmap_manager = compositor_deps_->GetSharedBitmapManager();
   params.gpu_memory_buffer_manager =
       compositor_deps_->GetGpuMemoryBufferManager();
   params.settings = &settings;
   params.task_graph_runner = compositor_deps_->GetTaskGraphRunner();
   params.main_task_runner =
       compositor_deps_->GetCompositorMainThreadTaskRunner();
   if (settings.use_external_begin_frame_source) {
     params.external_begin_frame_source =
         delegate_->CreateExternalBeginFrameSource();
-  } else {
-    DCHECK(settings.use_output_surface_begin_frame_source);
   }
   params.animation_host = cc::AnimationHost::CreateMainInstance();
 
   if (cmd->HasSwitch(switches::kUseRemoteCompositing)) {
     DCHECK(!threaded_);
     params.image_serialization_processor =
         compositor_deps_->GetImageSerializationProcessor();
     layer_tree_host_ = cc::LayerTreeHost::CreateRemoteServer(this, &params);
   } else if (!threaded_) {
     // Single-threaded layout tests.
@@ skipping 172 matching lines @@
     // raster-on-demand already, so now we reserve 50% _only_ to avoid
     // raster-on-demand, and use 50% of the memory otherwise.
     settings.max_memory_for_prepaint_percentage = 50;
   }
   // Webview does not own the surface so should not clear it.
   settings.renderer_settings.should_clear_root_render_pass =
       !using_synchronous_compositor;
 
   // TODO(danakj): Only do this on low end devices.
   settings.create_low_res_tiling = true;
+
+  settings.use_external_begin_frame_source = true;
+
 #else  // defined(OS_ANDROID)
 #if !defined(OS_MACOSX)
   if (ui::ShouldHideScrollbars()) {
     settings.scrollbar_animator = cc::LayerTreeSettings::NO_ANIMATOR;
     settings.solid_color_scrollbar_color = SK_ColorTRANSPARENT;
   } else if (ui::IsOverlayScrollbarEnabled()) {
     settings.scrollbar_animator = cc::LayerTreeSettings::THINNING;
     settings.solid_color_scrollbar_color = SkColorSetARGB(128, 128, 128, 128);
   } else {
     settings.scrollbar_animator = cc::LayerTreeSettings::LINEAR_FADE;
@@ skipping 16 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;
-
-  // TODO(enne): fold external BFS into output surface BFS.
-  if (cmd.HasSwitch(switches::kUseRemoteCompositing)) {
-    settings.use_output_surface_begin_frame_source = true;
-    settings.use_external_begin_frame_source = false;
-  } else {
-    settings.use_output_surface_begin_frame_source = false;
-    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;
   }
 
   settings.max_staging_buffer_usage_in_bytes = 32 * 1024 * 1024;  // 32MB
   // Use 1/4th of staging buffers on low-end devices.
   if (base::SysInfo::IsLowEndDevice())
     settings.max_staging_buffer_usage_in_bytes /= 4;
 
   cc::ManagedMemoryPolicy current = settings.memory_policy_;
   settings.memory_policy_ = GetGpuMemoryPolicy(current);
 
   settings.use_cached_picture_raster =
       !cmd.HasSwitch(cc::switches::kDisableCachedPictureRaster);
 
+  if (cmd.HasSwitch(switches::kUseRemoteCompositing))
+    settings.use_external_begin_frame_source = false;
+
   return settings;
 }
 
 // static
 cc::ManagedMemoryPolicy RenderWidgetCompositor::GetGpuMemoryPolicy(
     const cc::ManagedMemoryPolicy& policy) {
   cc::ManagedMemoryPolicy actual = policy;
   actual.bytes_limit_when_visible = 0;
 
   // If the value was overridden on the command line, use the specified value.
@@ skipping 624 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