Rename composited selection anchor/focus to start/end

cc/trees/layer_tree_impl.h

Index: cc/trees/layer_tree_impl.h
diff --git a/cc/trees/layer_tree_impl.h b/cc/trees/layer_tree_impl.h
index df39dcd2fdce8ab361758578ab45d59a627644b0..792f93ae24d0c3419921dbbc9f2213727fa08c57 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -264,13 +264,13 @@ class CC_EXPORT LayerTreeImpl {
   LayerImpl* FindLayerThatIsHitByPointInTouchHandlerRegion(
       const gfx::PointF& screen_space_point);
 
-  void RegisterSelection(const LayerSelectionBound& anchor,
-                         const LayerSelectionBound& focus);
+  void RegisterSelection(const LayerSelectionBound& start,
+                         const LayerSelectionBound& end);
 
   // Compute the current selection handle location and visbility with respect to
   // the viewport.
-  void GetViewportSelection(ViewportSelectionBound* anchor,
-                            ViewportSelectionBound* focus);
+  void GetViewportSelection(ViewportSelectionBound* start,
+                            ViewportSelectionBound* end);
 
   void RegisterPictureLayerImpl(PictureLayerImpl* layer);
   void UnregisterPictureLayerImpl(PictureLayerImpl* layer);
@@ -296,8 +296,8 @@ class CC_EXPORT LayerTreeImpl {
   LayerImpl* inner_viewport_scroll_layer_;
   LayerImpl* outer_viewport_scroll_layer_;
 
-  LayerSelectionBound selection_anchor_;
-  LayerSelectionBound selection_focus_;
+  LayerSelectionBound selection_start_;
+  LayerSelectionBound selection_end_;
 
   float page_scale_factor_;
   float page_scale_delta_;