Route selection bounds updates through the compositor

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 95f702fb549f2b8a6c518737eb360dfa64c978e1..58ffc319c6ce30270523c605dc489d3c776c97ce 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -47,6 +47,7 @@ class ResourceProvider;
 class TileManager;
 class UIResourceRequest;
 struct RendererCapabilities;
+struct SelectionHandle;
 
 typedef std::list<UIResourceRequest> UIResourceRequestQueue;
 
@@ -259,9 +260,17 @@ class CC_EXPORT LayerTreeImpl {
   LayerImpl* FindLayerThatIsHitByPointInTouchHandlerRegion(
       const gfx::PointF& screen_space_point);
 
+  void RegisterSelection(int start_layer_id,
+                         const SelectionHandle& start_handle,
+                         int end_layer_id,
+                         const SelectionHandle& end_handle);
+  void GetViewportSelection(SelectionHandle* start_handle,
+                            SelectionHandle* end_handle);
+
  protected:
   explicit LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl);
   void ReleaseResourcesRecursive(LayerImpl* current);
+  void ClearSelection();
 
   LayerTreeHostImpl* layer_tree_host_impl_;
   int source_frame_number_;
@@ -280,6 +289,11 @@ class CC_EXPORT LayerTreeImpl {
   LayerImpl* inner_viewport_scroll_layer_;
   LayerImpl* outer_viewport_scroll_layer_;
 
+  LayerImpl* start_selection_layer_;
+  SelectionHandle start_selection_handle_;
+  LayerImpl* end_selection_layer_;
+  SelectionHandle end_selection_handle_;
+
   float page_scale_factor_;
   float page_scale_delta_;
   float sent_page_scale_delta_;