Plumb LatencyInfo through aura.

content/browser/renderer_host/image_transport_factory.cc

Index: content/browser/renderer_host/image_transport_factory.cc
diff --git a/content/browser/renderer_host/image_transport_factory.cc b/content/browser/renderer_host/image_transport_factory.cc
index 1e566ac2f1e7d241d09bcf2e36f09a0ee6a4e625..eecbf3feb32a4ccb0a5b3a04497ba0576d52c00b 100644
--- a/content/browser/renderer_host/image_transport_factory.cc
+++ b/content/browser/renderer_host/image_transport_factory.cc
@@ -353,6 +353,29 @@ class BrowserCompositorOutputSurface
                    compositor_, timebase, interval));
   }
 
+  virtual void SwapBuffers(const ui::LatencyInfo& latency_info) OVERRIDE {
+    WebGraphicsContext3DCommandBufferImpl* command_buffer =
+        static_cast<WebGraphicsContext3DCommandBufferImpl*>(context3d());
+    CommandBufferProxyImpl* command_buffer_proxy =
+        command_buffer->GetCommandBufferProxy();
+    DCHECK(command_buffer_proxy);
+    context3d()->shallowFlushCHROMIUM();
+    command_buffer_proxy->SetLatencyInfo(latency_info);
+    OutputSurface::SwapBuffers(latency_info);
+  }

[piman, 2013/05/31 04:13:44]

Since this is all the same as CompositorOutputSurface::SwapBuffers, it's
tempting to move it to cc::OutputSurface::SwapBuffers.

Is the holdout that WebGraphicsContext3D doesn't have a way to set the latency
info without unsafe casts?

[jbauman, 2013/05/31 21:51:36]

Yeah, the WebGraphicsContext3D has no notion of the LatencyInfo (being in Blink
and all that).

+
+  virtual void PostSubBuffer(gfx::Rect rect,
+                             const ui::LatencyInfo& latency_info) OVERRIDE {
+    WebGraphicsContext3DCommandBufferImpl* command_buffer =
+        static_cast<WebGraphicsContext3DCommandBufferImpl*>(context3d());
+    CommandBufferProxyImpl* command_buffer_proxy =
+        command_buffer->GetCommandBufferProxy();
+    DCHECK(command_buffer_proxy);
+    context3d()->shallowFlushCHROMIUM();
+    command_buffer_proxy->SetLatencyInfo(latency_info);
+    OutputSurface::PostSubBuffer(rect, latency_info);
+  }
+
  private:
   int surface_id_;
   scoped_refptr<BrowserCompositorOutputSurfaceProxy> output_surface_proxy_;