Update the window labels if they change in overview mode.

ui/aura/window.cc

Index: ui/aura/window.cc
diff --git a/ui/aura/window.cc b/ui/aura/window.cc
index 7ce4dec0431140db73f8351ecff676056a762a45..7eea861e61df66e8aced2740b7f187cef199b1f0 100644
--- a/ui/aura/window.cc
+++ b/ui/aura/window.cc
@@ -305,6 +305,13 @@ void Window::SetName(const std::string& name) {
     UpdateLayerName();
 }
 
+void Window::SetTitle(const base::string16& title) {
+  title_ = title;
+  FOR_EACH_OBSERVER(WindowObserver,
+                    observers_,
+                    OnWindowTitleChanged(this));
+}
+
 void Window::SetTransparent(bool transparent) {
   transparent_ = transparent;
   if (layer())