cc : Make tree synchronization independent of layer tree hierarchy (2)

cc/layers/layer.h

Index: cc/layers/layer.h
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index 64540492fc8c5c561f5b61c1e3a0eb185b8189fe..300540108f625801f73a1d7cd7f2684b4e62b217 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -384,14 +384,10 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
                           const LayerIdMap& layer_map);
 
   // This method is similar to PushPropertiesTo, but instead of pushing to
-  // a LayerImpl, it pushes the properties to proto::LayerProperties. It adds
-  // this layer to the proto::LayerUpdate if it or any of its descendants
-  // have changed properties. If this layer contains changed properties, the
-  // properties themselves will also be pushed the proto::LayerProperties.
-  // Similarly to PushPropertiesTo, this method also resets
-  // |needs_push_properties_| and |num_dependents_need_push_properties_|.
-  // Returns whether any of the descendants have changed properties.
-  bool ToLayerPropertiesProto(proto::LayerUpdate* layer_update);
+  // a LayerImpl, it pushes the properties to proto::LayerProperties. It is
+  // called only on layers that have changed properties. The properties
+  // themselves are pushed to proto::LayerProperties.
+  void ToLayerPropertiesProto(proto::LayerUpdate* layer_update);
 
   // Read all property values from the given LayerProperties object and update
   // the current layer. The values for |needs_push_properties_| and
@@ -419,13 +415,7 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
   }
 
   void SetNeedsPushProperties();
-  bool needs_push_properties() const { return needs_push_properties_; }
-  bool descendant_needs_push_properties() const {
-    return num_dependents_need_push_properties_ > 0;
-  }
-  void reset_needs_push_properties_for_testing() {
-    needs_push_properties_ = false;
-  }
+  void ResetNeedsPushPropertiesForTesting();
 
   virtual void RunMicroBenchmark(MicroBenchmark* benchmark);
 
@@ -562,39 +552,20 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
 
   void AddDependentNeedsPushProperties();
   void RemoveDependentNeedsPushProperties();
-  bool parent_should_know_need_push_properties() const {
-    return needs_push_properties() || descendant_needs_push_properties();
-  }
 
   bool IsPropertyChangeAllowed() const;
 
   // Serialize all the necessary properties to be able to reconstruct this Layer
-  // into proto::LayerProperties. This function must not set values for
-  // |needs_push_properties_| or |num_dependents_need_push_properties_| as they
-  // are dealt with at a higher level. This is only called if
-  // |needs_push_properties_| is set. For descendants of Layer, implementations
-  // must first call their parent class. This method is not marked as const
+  // into proto::LayerProperties. This method is not marked as const
   // as some implementations need reset member fields, similarly to
   // PushPropertiesTo().
   virtual void LayerSpecificPropertiesToProto(proto::LayerProperties* proto);
 
   // Deserialize all the necessary properties from proto::LayerProperties into
-  // this Layer. This function must not set values for |needs_push_properties_|
-  // or |num_dependents_need_push_properties_| as they are dealt with at a
-  // higher level. This is only called if |needs_push_properties_| is set. For
-  // descendants of Layer, implementations must first call their parent class.
+  // this Layer.
   virtual void FromLayerSpecificPropertiesProto(
       const proto::LayerProperties& proto);
 
-  // This flag is set when the layer needs to push properties to the impl
-  // side.
-  bool needs_push_properties_;
-
-  // The number of direct children or dependent layers that need to be recursed
-  // to in order for them or a descendent of them to push properties to the impl
-  // side.
-  int num_dependents_need_push_properties_;
-
   // The update rect is the region of the compositor resource that was
   // actually updated by the compositor. For layers that may do updating
   // outside the compositor's control (i.e. plugin layers), this information