Remove GpuHostMsg_FrameDrawn and replace with client channel swap ack

content/browser/compositor/gpu_browser_compositor_output_surface.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_browser_compositor_output_surface.h"
 
 #include "cc/output/compositor_frame.h"
+#include "cc/output/output_surface_client.h"
 #include "content/browser/compositor/reflector_impl.h"
+#include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
+#include "gpu/command_buffer/client/context_support.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 
 namespace content {
 
 GpuBrowserCompositorOutputSurface::GpuBrowserCompositorOutputSurface(
     const scoped_refptr<ContextProviderCommandBuffer>& context,
     int surface_id,
     IDMap<BrowserCompositorOutputSurface>* output_surface_map,
     const scoped_refptr<ui::CompositorVSyncManager>& vsync_manager,
     scoped_ptr<cc::OverlayCandidateValidator> overlay_candidate_validator)
     : BrowserCompositorOutputSurface(context,
                                      surface_id,
                                      output_surface_map,
                                      vsync_manager) {
   overlay_candidate_validator_ = overlay_candidate_validator.Pass();
 }
 
 GpuBrowserCompositorOutputSurface::~GpuBrowserCompositorOutputSurface() {}
 
 void GpuBrowserCompositorOutputSurface::SwapBuffers(
     cc::CompositorFrame* frame) {
   DCHECK(frame->gl_frame_data);
 
   ContextProviderCommandBuffer* provider_command_buffer =
       static_cast<ContextProviderCommandBuffer*>(context_provider_.get());
   CommandBufferProxyImpl* command_buffer_proxy =
       provider_command_buffer->GetCommandBufferProxy();
   DCHECK(command_buffer_proxy);
-  command_buffer_proxy->SetLatencyInfo(frame->metadata.latency_info);
+  command_buffer_proxy->SetLatencyInfo(frame->metadata.latency_info,
+        base::Bind(&GpuBrowserCompositorOutputSurface::OnSwapBuffersCompleted,
+                   base::Unretained(this)));

[piman, 2014/10/07 02:30:39]

Because ContextProvider is refcounted, it might outlive the
GpuBrowserCompositorOutputSurface, and so the context might receive a callback
after the GpuBrowserCompositorOutputSurface was destroyed.
Should we use a weak pointer, or provide a mechanism to cancel the callbacks?

[no sievers, 2014/10/07 19:47:24]

Done. I've used CancelableCallback (which essentially wraps a WeakPtr) just to
discourage more weakptr bindings a bit. Also the base class already has a
WeakPtr factory so it can get a bit confusing.

 
   if (reflector_.get()) {
     if (frame->gl_frame_data->sub_buffer_rect ==
         gfx::Rect(frame->gl_frame_data->size))
       reflector_->OnSwapBuffers();
     else
       reflector_->OnPostSubBuffer(frame->gl_frame_data->sub_buffer_rect);
   }
 
-  OutputSurface::SwapBuffers(frame);
+  if (frame->gl_frame_data->sub_buffer_rect ==
+      gfx::Rect(frame->gl_frame_data->size)) {
+    context_provider_->ContextSupport()->Swap();
+  } else {
+    context_provider_->ContextSupport()->PartialSwapBuffers(
+        frame->gl_frame_data->sub_buffer_rect);
+  }
+
+  client_->DidSwapBuffers();
+}
+
+void GpuBrowserCompositorOutputSurface::OnSwapBuffersCompleted(
+    const std::vector<ui::LatencyInfo>& latency_info) {
+  RenderWidgetHostImpl::CompositorFrameDrawn(latency_info);
+  BrowserCompositorOutputSurface::OnSwapBuffersComplete();
 }
 
 }  // namespace content