Hide location bar on WebKit programmatic 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 20ba6e4b6544e4205445f572d0b963ba779dab25..ceda1a647f5500f4a8ccda7695f250eb3cddcea8 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -981,6 +981,15 @@ void LayerTreeHost::EnableHidingTopControls(bool enable) {
                  top_controls_manager_weak_ptr_, enable));
 }
 
+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;