cc: Block commit on activate by setting a flag on LayerTreeHost.

cc/layers/layer.h

 // Copyright 2010 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 CC_LAYERS_LAYER_H_
 #define CC_LAYERS_LAYER_H_
 
 #include <set>
 #include <string>
 
@@ skipping 379 matching lines @@
       LayerAnimationEventObserver* animation_observer);
   void RemoveLayerAnimationEventObserver(
       LayerAnimationEventObserver* animation_observer);
 
   virtual Region VisibleContentOpaqueRegion() const;
 
   virtual PaintedScrollbarLayer* ToScrollbarLayer();
 
   gfx::Rect LayerRectToContentRect(const gfx::RectF& layer_rect) const;
 
-  // In impl-side painting, this returns true if this layer type is not
-  // compatible with the main thread running freely, such as a double-buffered
-  // canvas that doesn't want to be triple-buffered across all three trees.
-  virtual bool BlocksPendingCommit() const;
-  // Returns true if anything in this tree blocksPendingCommit.
-  bool BlocksPendingCommitRecursive() const;
-
   virtual skia::RefPtr<SkPicture> GetPicture() const;
 
   virtual bool CanClipSelf() const;
 
   // Constructs a LayerImpl of the correct runtime type for this Layer type.
   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
 
   bool NeedsDisplayForTesting() const { return !update_rect_.IsEmpty(); }
   void ResetNeedsDisplayForTesting() { update_rect_ = gfx::RectF(); }
 
@@ skipping 31 matching lines @@
   // that it needs a commit yet.  It needs CalcDrawProperties and UpdateLayers
   // before it knows whether or not a commit is required.
   void SetNeedsUpdate();
   // Called when a property has been modified in a way that the layer
   // knows immediately that a commit is required.  This implies SetNeedsUpdate
   // as well as SetNeedsPushProperties to push that property.
   void SetNeedsCommit();
   // Called when there's been a change in layer structure.  Implies both
   // SetNeedsUpdate and SetNeedsCommit, but not SetNeedsPushProperties.
   void SetNeedsFullTreeSync();
-  bool IsPropertyChangeAllowed() const;
+
+  // Called when the next commit should wait until the pending tree is activated
+  // before finishing the commit and unblocking the main thread. Used to ensure
+  // unused resources on the impl thread are returned before commit completes.
+  void SetNextCommitWaitsForActivation();
 
   void SetNeedsPushProperties();
   void AddDependentNeedsPushProperties();
   void RemoveDependentNeedsPushProperties();
   bool parent_should_know_need_push_properties() const {
     return needs_push_properties() || descendant_needs_push_properties();
   }
 
+  bool IsPropertyChangeAllowed() const;
+
   // If this layer has a scroll parent, it removes |this| from its list of
   // scroll children.
   void RemoveFromScrollTree();
 
   // If this layer has a clip parent, it removes |this| from its list of clip
   // children.
   void RemoveFromClipTree();
 
   void reset_raster_scale_to_unknown() { raster_scale_ = 0.f; }
 
@@ skipping 107 matching lines @@
   DrawProperties<Layer, RenderSurface> draw_properties_;
 
   PaintProperties paint_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_H_