Delete background tab IOSurfaces on Mac.

content/browser/renderer_host/render_widget_host_impl.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_RENDERER_HOST_RENDER_WIDGET_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_IMPL_H_
 #pragma once
 
 #include <deque>
 #include <string>
@@ skipping 162 matching lines @@
   bool is_accelerated_compositing_active() {
     return is_accelerated_compositing_active_;
   }
 
   // Notifies the RenderWidgetHost that the View was destroyed.
   void ViewDestroyed();
 
   // Indicates if the page has finished loading.
   void SetIsLoading(bool is_loading);
 
-  // Get access to the widget's backing store.  If a resize is in progress,
-  // then the current size of the backing store may be less than the size of
-  // the widget's view.  If you pass |force_create| as true, then the backing
-  // store will be created if it doesn't exist. Otherwise, NULL will be returned
-  // if the backing store doesn't already exist. It will also return NULL if the
+  // Check for the existance of a BackingStore of the given |desired_size| and
+  // return it if it exists. If the BackingStore is GPU, true is returned and
+  // |*backing_store| is set to NULL.
+  bool TryGetBackingStore(const gfx::Size& desired_size,
+                          BackingStore** backing_store);
+
+  // Get access to the widget's backing store matching the size of the widget's
+  // view. If you pass |force_create| as true, then GetBackingStore may block
+  // for the renderer to send a new frame. Otherwise, NULL will be returned if
+  // the backing store doesn't already exist. It will also return NULL if the
   // backing store could not be created.
+  //
+  // Mac only: NULL may also be returned if the last frame was GPU accelerated.
+  // Call GetView()->HasAcceleratedSurface to determine if the last frame was
+  // accelerated.
   BackingStore* GetBackingStore(bool force_create);
 
   // Allocate a new backing store of the given size. Returns NULL on failure
   // (for example, if we don't currently have a RenderWidgetHostView.)
   BackingStore* AllocBackingStore(const gfx::Size& size);
 
   // When a backing store does asynchronous painting, it will call this function
   // when it is done with the DIB. We will then forward a message to the
   // renderer to send another paint.
   void DonePaintingToBackingStore();
@@ skipping 259 matching lines @@
   void RendererIsResponsive();
 
   // IPC message handlers
   void OnMsgRenderViewReady();
   void OnMsgRenderViewGone(int status, int error_code);
   void OnMsgClose();
   void OnMsgRequestMove(const gfx::Rect& pos);
   void OnMsgSetTooltipText(const string16& tooltip_text,
                            WebKit::WebTextDirection text_direction_hint);
   void OnMsgPaintAtSizeAck(int tag, const gfx::Size& size);
+  void OnCompositorSurfaceBuffersSwapped(int32 surface_id,
+                                         uint64 surface_handle,
+                                         int32 route_id,
+                                         int32 gpu_process_host_id);
   void OnMsgUpdateRect(const ViewHostMsg_UpdateRect_Params& params);
   void OnMsgUpdateIsDelayed();
   void OnMsgInputEventAck(WebKit::WebInputEvent::Type event_type,
                           bool processed);
   virtual void OnMsgFocus();
   virtual void OnMsgBlur();
   void OnMsgDidChangeNumTouchEvents(int count);
 
   void OnMsgSetCursor(const WebCursor& cursor);
   void OnMsgTextInputStateChanged(ui::TextInputType type,
@@ skipping 167 matching lines @@
   // This value denotes the number of input events yet to be acknowledged
   // by the renderer.
   int in_flight_event_count_;
 
   // This timer runs to check if time_when_considered_hung_ has past.
   base::OneShotTimer<RenderWidgetHostImpl> hung_renderer_timer_;
 
   // Flag to detect recursive calls to GetBackingStore().
   bool in_get_backing_store_;
 
+  // Flag to trigger the GetBackingStore method to abort early.
+  bool abort_get_backing_store_;
+
   // Set when we call DidPaintRect/DidScrollRect on the view.
   bool view_being_painted_;
 
   // Used for UMA histogram logging to measure the time for a repaint view
   // operation to finish.
   base::TimeTicks repaint_start_time_;
 
   // Queue of keyboard events that we need to track.
   typedef std::deque<NativeWebKeyboardEvent> KeyQueue;
 
@@ skipping 44 matching lines @@
   base::WeakPtrFactory<RenderWidgetHostImpl> weak_factory_;
 
   scoped_ptr<TapSuppressionController> tap_suppression_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_IMPL_H_