Support browser side thumbnailing for GPU composited pages on Windows.

content/browser/gpu/gpu_surface_tracker.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_BROWSER_GPU_GPU_SURFACE_TRACKER_H_
 #define CONTENT_BROWSER_GPU_GPU_SURFACE_TRACKER_H_
 
 #include <map>
+#include <vector>
 
 #include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
 #include "base/synchronization/lock.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/size.h"
 
+class GpuSurfaceReader;
+
 // This class is responsible for managing rendering surfaces exposed to the
 // GPU process. Every surface gets registered to this class, and gets an ID.
 // All calls to and from the GPU process, with the exception of
 // CreateViewCommandBuffer, refer to the rendering surface by its ID.
 // This class is thread safe.
 //
 // Note: The ID can exist before the actual native handle for the surface is
 // created, for example to allow giving a reference to it to a renderer, so that
 // it is unamibiguously identified.
 class GpuSurfaceTracker {
  public:
+  struct SurfaceInfo {

[apatrick_chromium, 2012/03/07 20:39:37]

If it weren't for GpuSurfaceReader, this could remain private.

[mazda, 2012/03/08 13:14:28]

Done.

+    int renderer_id;
+    int render_widget_id;
+    gfx::AcceleratedWidget native_widget;
+    gfx::GLSurfaceHandle handle;
+  };
+
   // Gets the global instance of the surface tracker.
   static GpuSurfaceTracker* Get() { return GetInstance(); }
 
   // Adds a surface for a given RenderWidgetHost. |renderer_id| is the renderer
   // process ID, |render_widget_id| is the RenderWidgetHost route id within that
   // renderer. Returns the surface ID.
   int AddSurfaceForRenderer(int renderer_id, int render_widget_id);
 
   // Looks up a surface for a given RenderWidgetHost. Returns the surface
   // ID, or 0 if not found.
@@ skipping 14 matching lines @@
                                    int* render_widget_id);
 
   // Sets the native handle for the given surface.
   // Note: This is an O(log N) lookup.
   void SetSurfaceHandle(int surface_id, const gfx::GLSurfaceHandle& handle);
 
   // Gets the native handle for the given surface.
   // Note: This is an O(log N) lookup.
   gfx::GLSurfaceHandle GetSurfaceHandle(int surface_id);
 
+  // Copies the image data of the the given surface to |out|. The image data
+  // is transformed so that it fits in |size|.
+  bool CopySurface(int surface_id,
+                   const gfx::Size& size,
+                   std::vector<unsigned char>* out);
+
 #if defined(OS_WIN) && !defined(USE_AURA)
   // This is a member of GpuSurfaceTracker because it holds the lock for its
   // duration. This prevents the AcceleratedSurface that it posts to from being
   // destroyed by the main thread during that time. This function is only called
   // on the IO thread. This function only posts tasks asynchronously. If it
   // were to synchronously call the UI thread, there would be a possiblity of
   // deadlock.
   void AsyncPresentAndAcknowledge(int surface_id,
                                   const gfx::Size& size,
                                   int64 surface_handle,
                                   const base::Closure& completion_task);
 #endif
 
   // Gets the global instance of the surface tracker. Identical to Get(), but
   // named that way for the implementation of Singleton.
   static GpuSurfaceTracker* GetInstance();
 
  private:
-  struct SurfaceInfo {
-    int renderer_id;
-    int render_widget_id;
-    gfx::AcceleratedWidget native_widget;
-    gfx::GLSurfaceHandle handle;
-  };
   typedef std::map<int, SurfaceInfo> SurfaceMap;
 
   friend struct DefaultSingletonTraits<GpuSurfaceTracker>;
 
   GpuSurfaceTracker();
   ~GpuSurfaceTracker();
 
   base::Lock lock_;
   SurfaceMap surface_map_;
   int next_surface_id_;
+  scoped_ptr<GpuSurfaceReader> reader_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuSurfaceTracker);
 };
 
 #endif  // CONTENT_BROWSER_GPU_GPU_SURFACE_TRACKER_H_