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 dd572268a085cf6af02492263108d314a65076e6..2e14e5acd94c7954ac508ee74db2cdcd23888b3a 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -975,6 +975,15 @@ 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;