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

cc/surfaces/display.h

Index: cc/surfaces/display.h
diff --git a/cc/surfaces/display.h b/cc/surfaces/display.h
index 93606ba6e8c2bb0e974ca5dba0fa515b9709a0ba..41b6c64729943b58c84d4a713f7b66b7c5ff43ca 100644
--- a/cc/surfaces/display.h
+++ b/cc/surfaces/display.h
@@ -11,6 +11,7 @@
 #include "cc/resources/returned_resource.h"
 #include "cc/surfaces/surface_aggregator.h"
 #include "cc/surfaces/surface_id.h"
+#include "cc/surfaces/surface_manager.h"
 #include "cc/surfaces/surfaces_export.h"
 
 namespace gfx {
@@ -28,13 +29,14 @@ class Surface;
 class SurfaceAggregator;
 class SurfaceIdAllocator;
 class SurfaceFactory;
-class SurfaceManager;
 
 // A Display produces a surface that can be used to draw to a physical display
 // (OutputSurface). The client is responsible for creating and sizing the
 // surface IDs used to draw into the display and deciding when to draw.
-class CC_SURFACES_EXPORT Display : public OutputSurfaceClient,
-                                   public RendererClient {
+class CC_SURFACES_EXPORT Display
+    : public OutputSurfaceClient,
+      public RendererClient,
+      public SurfaceManager::SurfaceDamageObserver {
  public:
   Display(DisplayClient* client,
           SurfaceManager* manager,
@@ -72,6 +74,9 @@ class CC_SURFACES_EXPORT Display : public OutputSurfaceClient,
   virtual void SetFullRootLayerDamage() OVERRIDE {}
   virtual void RunOnDemandRasterTask(Task* on_demand_raster_task) OVERRIDE {}
 
+  // SurfaceManager::SurfaceDamageObserver implementation.
+  virtual void OnSurfaceDamaged(SurfaceId surface) OVERRIDE;
+
  private:
   void InitializeOutputSurface();
 
@@ -86,6 +91,8 @@ class CC_SURFACES_EXPORT Display : public OutputSurfaceClient,
   scoped_ptr<SurfaceAggregator> aggregator_;
   scoped_ptr<DirectRenderer> renderer_;
 
+  std::set<SurfaceId> contained_surfaces_;
+
   DISALLOW_COPY_AND_ASSIGN(Display);
 };