Fix menu crash

ui/aura_shell/stacking_controller.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/aura_shell/stacking_controller.h"
 
 #include "ui/aura/desktop.h"
 #include "ui/aura/window.h"
 #include "ui/aura_shell/shell.h"
 #include "ui/aura_shell/shell_window_ids.h"
@@ skipping 24 matching lines @@
 StackingController::~StackingController() {
 }
 
 // static
 aura::Window* StackingController::GetActivatableWindow(aura::Window* window) {
   aura::Window* parent = window->parent();
   aura::Window* child = window;
   while (parent) {
     if (SupportsChildActivation(parent))
       return child;
+    // If |child| isn't activatable, but has transient parent, trace
+    // that path instead.
+    if (child->transient_parent())
+      return GetActivatableWindow(child->transient_parent());
     parent = parent->parent();
     child = child->parent();
   }
   return false;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // StackingController, aura::StackingClient implementation:
 
 void StackingController::AddChildToDefaultParent(aura::Window* window) {
@@ skipping 31 matching lines @@
   }
   return NULL;
 }
 
 
 ////////////////////////////////////////////////////////////////////////////////
 // StackingController, private:
 
 }  // namespace internal
 }  // namespace aura_shell