Fix "modal isn't modal in multi displays" issue

ash/shell.cc

 // Copyright (c) 2012 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 "ash/shell.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 
@@ skipping 1185 matching lines @@
   aura::client::SetEventClient(root_window, event_client_.get());
 
   aura::client::SetWindowMoveClient(root_window,
       toplevel_window_event_handler_.get());
   root_window->AddPreTargetHandler(toplevel_window_event_handler_.get());
   root_window->AddPostTargetHandler(toplevel_window_event_handler_.get());
 }
 
 bool Shell::CanWindowReceiveEvents(aura::Window* window) {
   RootWindowControllerList controllers = GetAllRootWindowControllers();
-  for (RootWindowControllerList::iterator iter = controllers.begin();
-       iter != controllers.end(); ++iter) {
-    SystemModalContainerLayoutManager* layout_manager =
-        (*iter)->GetSystemModalLayoutManager(window);
-    if (layout_manager && layout_manager->CanWindowReceiveEvents(window))
-      return true;
-    // Allow events to fall through to the virtual keyboard even if displaying
-    // a system modal dialog.
-    if ((*iter)->IsVirtualKeyboardWindow(window))
+  for (RootWindowController* controller : controllers) {
+    if (controller->CanWindowReceiveEvents(window))
       return true;
   }
-
   return false;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Shell, ui::EventTarget overrides:
 
 bool Shell::CanAcceptEvent(const ui::Event& event) {
   return true;
 }
 
@@ skipping 15 matching lines @@
 
 void Shell::OnWindowActivated(
     aura::client::ActivationChangeObserver::ActivationReason reason,
     aura::Window* gained_active,
     aura::Window* lost_active) {
   if (gained_active)
     target_root_window_ = gained_active->GetRootWindow();
 }
 
 }  // namespace ash