Enqueuing new frames in a Surface should cause Displays to reaggregate it

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 <string>
 
 #include "base/containers/hash_tables.h"
@@ skipping 174 matching lines @@
   // Sets the background color used for areas that aren't covered by
   // the |root_layer|.
   void SetBackgroundColor(SkColor color);
 
   // Returns the widget for this compositor.
   gfx::AcceleratedWidget widget() const { return widget_; }
 
   // 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_;
+  }
+
   // Compositor does not own observers. It is the responsibility of the
   // observer to remove itself when it is done observing.
   void AddObserver(CompositorObserver* observer);
   void RemoveObserver(CompositorObserver* observer);
   bool HasObserver(CompositorObserver* observer);
 
   void AddAnimationObserver(CompositorAnimationObserver* observer);
   void RemoveAnimationObserver(CompositorAnimationObserver* observer);
   bool HasAnimationObserver(CompositorAnimationObserver* observer);
 
@@ skipping 101 matching lines @@
   LayerAnimatorCollection layer_animator_collection_;
 
   base::WeakPtrFactory<Compositor> schedule_draw_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Compositor);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_COMPOSITOR_H_