cc: Introduce BeginFrame sequence numbers and acknowledgements.

content/browser/compositor/gpu_process_transport_factory.cc

 // Copyright 2014 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/browser/compositor/gpu_process_transport_factory.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 418 matching lines @@
       gpu::GpuChannelEstablishedCallback callback(
           base::Bind(&GpuProcessTransportFactory::EstablishedGpuChannel,
                      callback_factory_.GetWeakPtr(), compositor,
                      create_gpu_output_surface, num_attempts + 1));
       DCHECK(gpu_channel_factory_);
       gpu_channel_factory_->EstablishGpuChannel(callback);
       return;
     }
   }
 
-  std::unique_ptr<cc::SyntheticBeginFrameSource> begin_frame_source;
+  cc::SyntheticBeginFrameSource* synthetic_begin_frame_source;
   if (!compositor->GetRendererSettings().disable_display_vsync) {
-    begin_frame_source.reset(new cc::DelayBasedBeginFrameSource(
+    synthetic_begin_frame_source = new cc::DelayBasedBeginFrameSource(
         base::MakeUnique<cc::DelayBasedTimeSource>(
-            compositor->task_runner().get())));
+            compositor->task_runner().get()));
   } else {
-    begin_frame_source.reset(new cc::BackToBackBeginFrameSource(
+    synthetic_begin_frame_source = new cc::BackToBackBeginFrameSource(
         base::MakeUnique<cc::DelayBasedTimeSource>(
-            compositor->task_runner().get())));
+            compositor->task_runner().get()));
   }
+  std::unique_ptr<cc::BeginFrameSource> begin_frame_source(
+      synthetic_begin_frame_source);
 
   BrowserCompositorOutputSurface::UpdateVSyncParametersCallback vsync_callback =
       base::Bind(&ui::Compositor::SetDisplayVSyncParameters, compositor);
 
   std::unique_ptr<BrowserCompositorOutputSurface> display_output_surface;
 #if defined(ENABLE_VULKAN)
   std::unique_ptr<VulkanBrowserCompositorOutputSurface> vulkan_surface;
   if (vulkan_context_provider) {
     vulkan_surface.reset(new VulkanBrowserCompositorOutputSurface(
         vulkan_context_provider, vsync_callback));
@@ skipping 44 matching lines @@
         // Overlays are only supported on surfaceless output surfaces on Mac.
         if (!use_mus)
           validator = CreateOverlayCandidateValidator(compositor->widget());
 #endif
         if (!use_mus) {
           display_output_surface =
               base::MakeUnique<GpuBrowserCompositorOutputSurface>(
                   context_provider, vsync_callback, std::move(validator));
         } else {
 #if defined(USE_AURA)
+          std::unique_ptr<MusBrowserCompositorOutputSurface> mus_output_surface;
           if (compositor->window()) {
             // TODO(mfomitchev): Remove this clause once we complete the switch
             // to Aura-Mus.
-            display_output_surface =
+            mus_output_surface =
                 base::MakeUnique<MusBrowserCompositorOutputSurface>(
                     compositor->window(), context_provider,
                     GetGpuMemoryBufferManager(), vsync_callback,
                     std::move(validator));
           } else {
             aura::WindowTreeHost* host =
                 aura::WindowTreeHost::GetForAcceleratedWidget(
                     compositor->widget());
-            display_output_surface =
+            mus_output_surface =
                 base::MakeUnique<MusBrowserCompositorOutputSurface>(
                     host->window(), context_provider,
                     GetGpuMemoryBufferManager(), vsync_callback,
                     std::move(validator));
           }
+          // We use the ExternalBeginFrameSource provided by the output surface
+          // instead of our own synthetic one.
+          begin_frame_source.reset(new cc::DelegatingBeginFrameSource(
+              mus_output_surface->GetBeginFrameSource()));
+          synthetic_begin_frame_source = nullptr;
+          display_output_surface = std::move(mus_output_surface);
 #else
           NOTREACHED();
 #endif
         }
       }
     }
   }
 
   data->display_output_surface = display_output_surface.get();
-  data->begin_frame_source = begin_frame_source.get();
+  if (synthetic_begin_frame_source)
+    data->begin_frame_source = synthetic_begin_frame_source;
   if (data->reflector)
     data->reflector->OnSourceSurfaceReady(data->display_output_surface);
 
 #if defined(OS_WIN)
   gfx::RenderingWindowManager::GetInstance()->DoSetParentOnChild(
       compositor->widget());
 #endif
 
   std::unique_ptr<cc::DisplayScheduler> scheduler(new cc::DisplayScheduler(
-      begin_frame_source.get(), compositor->task_runner().get(),
+      compositor->task_runner().get(),
       display_output_surface->capabilities().max_frames_pending));
 
   // The Display owns and uses the |display_output_surface| created above.
   data->display = base::MakeUnique<cc::Display>(
       HostSharedBitmapManager::current(), GetGpuMemoryBufferManager(),
       compositor->GetRendererSettings(), compositor->frame_sink_id(),
       std::move(begin_frame_source), std::move(display_output_surface),
       std::move(scheduler), base::MakeUnique<cc::TextureMailboxDeleter>(
                                 compositor->task_runner().get()));
 
@@ skipping 319 matching lines @@
       shared_vulkan_context_provider_ =
           cc::VulkanInProcessContextProvider::Create();
     }
 
     shared_vulkan_context_provider_initialized_ = true;
   }
   return shared_vulkan_context_provider_;
 }
 
 }  // namespace content