Make RenderWidgetHostViewAura::CopyFromCompositingSurface readback layer

content/browser/renderer_host/render_widget_host_view_win.cc

 // Copyright (c) 2012 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/renderer_host/render_widget_host_view_win.h"
 
 #include <dwmapi.h>
 #include <InputScope.h>
 #include <wtsapi32.h>
 #pragma comment(lib, "wtsapi32.lib")
@@ skipping 756 matching lines @@
 
 void RenderWidgetHostViewWin::DidUpdateBackingStore(
     const gfx::Rect& scroll_rect,
     const gfx::Vector2d& scroll_delta,
     const std::vector<gfx::Rect>& copy_rects,
     const ui::LatencyInfo& latency_info) {
   software_latency_info_.MergeWith(latency_info);
   if (is_hidden_)
     return;
 
+  DidReceiveRendererFrame();

[piman, 2013/07/02 01:49:09]

So, on Windows, the accelerated swap doesn't get to the UI thread (it's routed
to a "presenter" thread). I'm not sure how this would work there, short of
posting a task to update the frame count. Maybe we can do that?

[danakj, 2013/07/03 18:05:39]

Hm. The GpuProcessHost calls the RWVImpl to tell it FrameSwapped. It could call
the RWHV->DidReceiveRendererFrame()?

+
   // Schedule invalidations first so that the ScrollWindowEx call is closer to
   // Redraw.  That minimizes chances of "flicker" resulting if the screen
   // refreshes before we have a chance to paint the exposed area.  Somewhat
   // surprisingly, this ordering matters.
 
   for (size_t i = 0; i < copy_rects.size(); ++i) {
     gfx::Rect pixel_rect = ui::win::DIPToScreenRect(copy_rects[i]);
     // Damage might not be DIP aligned.
     pixel_rect.Inset(-1, -1);
     RECT bounds = pixel_rect.ToRECT();
@@ skipping 2435 matching lines @@
   return new RenderWidgetHostViewWin(widget);
 }
 
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(
       WebKit::WebScreenInfo* results) {
   GetScreenInfoForWindow(0, results);
 }
 
 }  // namespace content