Route selection bounds updates through the compositor

cc/trees/layer_tree_host.h

Index: cc/trees/layer_tree_host.h
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index e77b86804239238cf6e767c0d6527c10a0c6aeab..c9cd5342b7c0caab0cb031235f3de81f4b169dc6 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -178,6 +178,11 @@ class CC_EXPORT LayerTreeHost {
     return outer_viewport_scroll_layer_.get();
   }
 
+  void RegisterSelection(scoped_refptr<Layer> start_layer,
+                         const SelectionHandle& start_handle,
+                         scoped_refptr<Layer> end_layer,
+                         const SelectionHandle& end_handle);
+
   const LayerTreeSettings& settings() const { return settings_; }
 
   void SetDebugState(const LayerTreeDebugState& debug_state);
@@ -441,6 +446,11 @@ class CC_EXPORT LayerTreeHost {
   scoped_refptr<Layer> inner_viewport_scroll_layer_;
   scoped_refptr<Layer> outer_viewport_scroll_layer_;
 
+  scoped_refptr<Layer> start_selection_layer_;
+  scoped_refptr<Layer> end_selection_layer_;
+  SelectionHandle start_selection_handle_;
+  SelectionHandle end_selection_handle_;
+
   SharedBitmapManager* shared_bitmap_manager_;
 
   ScopedPtrVector<SwapPromise> swap_promise_list_;