cc: Simplify the logic for deciding to update tile priorities.

cc/trees/layer_tree_impl.h

 // Copyright 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 CC_TREES_LAYER_TREE_IMPL_H_
 #define CC_TREES_LAYER_TREE_IMPL_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 103 matching lines @@
   SkColor background_color() const { return background_color_; }
   void set_background_color(SkColor color) { background_color_ = color; }
 
   bool has_transparent_background() const {
     return has_transparent_background_;
   }
   void set_has_transparent_background(bool transparent) {
     has_transparent_background_ = transparent;
   }
 
-  enum UpdateDrawPropertiesReason {
-    UPDATE_PENDING_TREE,
-    UPDATE_ACTIVE_TREE,
-    UPDATE_ACTIVE_TREE_FOR_DRAW
-  };
-
   gfx::Transform ImplTransform() const;
 
   void SetPageScaleFactorAndLimits(float page_scale_factor,
       float min_page_scale_factor, float max_page_scale_factor);
   void SetPageScaleDelta(float delta);
   float total_page_scale_factor() const {
     return page_scale_factor_ * page_scale_delta_;
   }
   float page_scale_factor() const { return page_scale_factor_; }
   float min_page_scale_factor() const { return min_page_scale_factor_; }
   float max_page_scale_factor() const { return max_page_scale_factor_; }
   float page_scale_delta() const  { return page_scale_delta_; }
   void set_sent_page_scale_delta(float delta) {
     sent_page_scale_delta_ = delta;
   }
   float sent_page_scale_delta() const { return sent_page_scale_delta_; }
 
-  // Updates draw properties and render surface layer list
-  void UpdateDrawProperties(UpdateDrawPropertiesReason reason);
+  // Updates draw properties and render surface layer list, as well as tile
+  // priorities.
+  void UpdateDrawProperties();
+
   void set_needs_update_draw_properties() {
     needs_update_draw_properties_ = true;
   }
   bool needs_update_draw_properties() const {
     return needs_update_draw_properties_;
   }
 
   void set_needs_full_tree_sync(bool needs) { needs_full_tree_sync_ = needs; }
   bool needs_full_tree_sync() const { return needs_full_tree_sync_; }
 
@@ skipping 96 matching lines @@
   bool needs_full_tree_sync_;
 
   LatencyInfo latency_info_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_IMPL_H_