Update from https://crrev.com/316786

cc/trees/occlusion_tracker.h

Index: cc/trees/occlusion_tracker.h
diff --git a/cc/trees/occlusion_tracker.h b/cc/trees/occlusion_tracker.h
index 4d6555a91e7b0abebf97f56f9527b485c6444d38..ff6f18dda9c93ee55308a9632bf451c5edae43a3 100644
--- a/cc/trees/occlusion_tracker.h
+++ b/cc/trees/occlusion_tracker.h
@@ -40,6 +40,8 @@ class CC_EXPORT OcclusionTracker {
   // and can be used outside of a layer walk to check occlusion.
   Occlusion GetCurrentOcclusionForLayer(
       const gfx::Transform& draw_transform) const;
+  Occlusion GetCurrentOcclusionForContributingSurface(
+      const gfx::Transform& draw_transform) const;
 
   // Called at the beginning of each step in the LayerIterator's front-to-back
   // traversal.
@@ -48,13 +50,6 @@ class CC_EXPORT OcclusionTracker {
   // traversal.
   void LeaveLayer(const LayerIteratorPosition<LayerType>& layer_iterator);
 
-  // Gives an unoccluded sub-rect of |content_rect| in the content space of the
-  // render_target owned by the layer. Used when considering occlusion for a
-  // contributing surface that is rendering into another target.
-  gfx::Rect UnoccludedContributingSurfaceContentRect(
-      const gfx::Rect& content_rect,
-      const gfx::Transform& draw_transform) const;
-
   // Gives the region of the screen that is not occluded by something opaque.
   Region ComputeVisibleRegionInScreen() const;
 
@@ -62,16 +57,6 @@ class CC_EXPORT OcclusionTracker {
     minimum_tracking_size_ = size;
   }
 
-  // The following is used for visualization purposes.
-  void set_occluding_screen_space_rects_container(
-      std::vector<gfx::Rect>* rects) {
-    occluding_screen_space_rects_ = rects;
-  }
-  void set_non_occluding_screen_space_rects_container(
-      std::vector<gfx::Rect>* rects) {
-    non_occluding_screen_space_rects_ = rects;
-  }
-
  protected:
   struct StackObject {
     StackObject() : target(0) {}
@@ -120,10 +105,6 @@ class CC_EXPORT OcclusionTracker {
   gfx::Rect screen_space_clip_rect_;
   gfx::Size minimum_tracking_size_;
 
-  // This is used for visualizing the occlusion tracking process.
-  std::vector<gfx::Rect>* occluding_screen_space_rects_;
-  std::vector<gfx::Rect>* non_occluding_screen_space_rects_;
-
   DISALLOW_COPY_AND_ASSIGN(OcclusionTracker);
 };