Route selection bounds updates through the compositor

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 7f6ae44ff74ef374156cae786bf66e6d54bdcd0a..deae8cad969195733f695b5dc7d13ad3208568cb 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -1381,6 +1381,9 @@ CompositorFrameMetadata LayerTreeHostImpl::MakeCompositorFrameMetadata() const {
     metadata.overdraw_bottom_height = overdraw_bottom_height_;
   }
 
+  active_tree_->GetViewportSelection(&metadata.start_selection_handle,
+                                     &metadata.end_selection_handle);
+
   if (!InnerViewportScrollLayer())
     return metadata;