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

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 <stddef.h>
 #include <stdint.h>
 
@@ skipping 366 matching lines @@
   void ToLayerNodeProto(proto::LayerNode* proto) const;
 
   // Recursively iterate over the given LayerNode proto and read the structure
   // into this node and its children. The |layer_map| should be used to look
   // for previously existing Layers, since they should be re-used between each
   // hierarchy update.
   void FromLayerNodeProto(const proto::LayerNode& proto,
                           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
   // |num_dependents_need_push_properties_| are always updated, but the rest
   // of |proto| is only read if |needs_push_properties_| is set.
   void FromLayerPropertiesProto(const proto::LayerProperties& proto);
 
   LayerTreeHost* layer_tree_host() { return layer_tree_host_; }
   const LayerTreeHost* layer_tree_host() const { return layer_tree_host_; }
 
   virtual ScrollbarLayerInterface* ToScrollbarLayer();
 
   virtual skia::RefPtr<SkPicture> GetPicture() 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::Rect(); }
 
   RenderingStatsInstrumentation* rendering_stats_instrumentation() const;
 
   const PaintProperties& paint_properties() const {
     return paint_properties_;
   }
 
   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);
 
   void Set3dSortingContextId(int id);
   int sorting_context_id() const { return sorting_context_id_; }
 
   void set_property_tree_sequence_number(int sequence_number) {
     property_tree_sequence_number_ = sequence_number;
   }
   int property_tree_sequence_number() { return property_tree_sequence_number_; }
@@ skipping 116 matching lines @@
   // Will recalculate whether the layer draws content and set draws_content_
   // appropriately.
   void UpdateDrawsContent(bool has_drawable_content);
   virtual bool HasDrawableContent() const;
 
   // Called when the layer's number of drawable descendants changes.
   void AddDrawableDescendants(int num);
 
   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
   // is not available and the update rect will remain empty.
   // Note this rect is in layer space (not content space).
   gfx::Rect update_rect_;
 
   scoped_refptr<Layer> mask_layer_;
 
   int layer_id_;
@@ skipping 122 matching lines @@
 
   std::vector<FrameTimingRequest> frame_timing_requests_;
   bool frame_timing_requests_dirty_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_H_