Support browser side thumbnailing for GPU composited pages on Windows.

content/public/browser/render_widget_host_view.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_H_
 #pragma once
 
 #if defined(TOOLKIT_USES_GTK)
 #include <gdk/gdk.h>
 #endif
 
 #include "content/common/content_export.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
 #include "ui/gfx/native_widget_types.h"
 
 class BrowserAccessibilityManager;
 
 namespace gfx {
 class Rect;
 class Size;
 }
 
+namespace skia {
+class PlatformCanvas;
+}
+
 namespace content {
 
 class RenderWidgetHost;
 
 // RenderWidgetHostView is an interface implemented by an object that acts as
 // the "View" portion of a RenderWidgetHost. The RenderWidgetHost and its
 // associated RenderProcessHost own the "Model" in this case which is the
 // child renderer process. The View is responsible for receiving events from
 // the surrounding environment and passing them to the RenderWidgetHost, and
 // for actually displaying the content of the RenderWidgetHost when it
@@ skipping 91 matching lines @@
 
   // TODO(joi): May be able to move into impl if RWHVMacDelegate stops
   // being exposed to Chrome.
   virtual void UnhandledWheelEvent(const WebKit::WebMouseWheelEvent& event) = 0;
 
   // Subclasses should override this method to do what is appropriate to set
   // the custom background for their platform.
   virtual void SetBackground(const SkBitmap& background) = 0;
   virtual const SkBitmap& GetBackground() = 0;
 
+  // Copies the contents of the compositing surface into the given
+  // (uninitialized) PlatformCanvas if any. Returns true on success, false
+  // otherwise.
+  virtual bool CopyFromCompositingSurface(const gfx::Size& size,

[jam, 2012/03/13 19:40:11]

this method doesn't need to be exposed to embedders (i.e. chrome), so instead it
should be on the RenderWidgetHostViewPort interface

[mazda, 2012/03/14 12:07:46]

Done.

+                                          skia::PlatformCanvas* output) = 0;
+
   // TODO(joi): Remove this when we remove the dependency by chrome/
   // on browser_accessibility* files in content.
   virtual BrowserAccessibilityManager*
       GetBrowserAccessibilityManager() const = 0;
 
 #if defined(OS_WIN) && !defined(USE_AURA)
   // The region specified will be transparent to mouse clicks.
   virtual void SetClickthroughRegion(SkRegion* region) {}
 #endif
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_H_