aura: Support releasing the OutputSurface()

ui/compositor/compositor.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 UI_COMPOSITOR_COMPOSITOR_H_
 #define UI_COMPOSITOR_COMPOSITOR_H_
 
 #include <list>
 #include <string>
 
@@ skipping 213 matching lines @@
   // The "authoritative" vsync interval, if provided, will override interval
   // reported from 3D context. This is typically the value reported by a more
   // reliable source, e.g, the platform display configuration.
   // In the particular case of ChromeOS -- this is the value queried through
   // XRandR, which is more reliable than the value queried through the 3D
   // context.
   void SetAuthoritativeVSyncInterval(const base::TimeDelta& interval);
 
   // Sets the widget for the compositor to render into.
   void SetAcceleratedWidget(gfx::AcceleratedWidget widget);
+  // Releases the widget previously set through SetAcceleratedWidget().
+  // After returning it will not be used for rendering anymore.
+  // The compositor must be set to invisible when taking away a widget.
+  gfx::AcceleratedWidget ReleaseAcceleratedWidget();
   gfx::AcceleratedWidget widget() const;
 
   // Returns the vsync manager for this compositor.
   scoped_refptr<CompositorVSyncManager> vsync_manager() const;
 
   // Returns the main thread task runner this compositor uses. Users of the
   // compositor generally shouldn't use this.
   scoped_refptr<base::SingleThreadTaskRunner> task_runner() const {
     return task_runner_;
   }
@@ skipping 125 matching lines @@
   cc::BeginFrameArgs missed_begin_frame_args_;
 
   base::WeakPtrFactory<Compositor> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Compositor);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_COMPOSITOR_H_