Hide location bar on Javascript-initiated scroll.

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 2072b7a1d041ed44e067117e163b791209c5e60c..24c3212d8204d99ea082a39db2641eabee2f4315 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -1059,6 +1059,15 @@ void LayerTreeHost::UpdateTopControlsState(bool enable_hiding,
                  animate));
 }
 
+void LayerTreeHost::ShowTopControls(bool show) {
+  if (!settings_.calculate_top_controls_position)
+    return;
+
+  proxy_->ImplThread()->PostTask(
+      base::Bind(&TopControlsManager::ShowTopControls,
+                 top_controls_manager_weak_ptr_, show));
+}
+
 bool LayerTreeHost::BlocksPendingCommit() const {
   if (!root_layer_)
     return false;