Make keyboard controller a singleton.

ash/root_window_controller.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/root_window_controller.h"
 
 #include <queue>
 #include <vector>
 
 #include "ash/ash_constants.h"
@@ skipping 432 matching lines @@
     // Release the old controller and close its background widget.
     SetWallpaperController(controller);
   }
 }
 
 void RootWindowController::CloseChildWindows() {
   mouse_event_target_.reset();
 
   // Deactivate keyboard container before closing child windows and shutting
   // down associated layout managers.
-  DeactivateKeyboard(Shell::GetInstance()->keyboard_controller());
+  DeactivateKeyboard(keyboard::KeyboardController::GetInstance());
 
   // panel_layout_manager_ needs to be shut down before windows are destroyed.
   if (panel_layout_manager_) {
     panel_layout_manager_->Shutdown();
     panel_layout_manager_ = NULL;
   }
   // docked_layout_manager_ needs to be shut down before windows are destroyed.
   if (docked_layout_manager_) {
     if (shelf_ && shelf_->shelf_layout_manager())
       docked_layout_manager_->RemoveObserver(shelf_->shelf_layout_manager());
@@ skipping 534 matching lines @@
   else
     DisableTouchHudProjection();
 }
 
 RootWindowController* GetRootWindowController(
     const aura::Window* root_window) {
   return root_window ? GetRootWindowSettings(root_window)->controller : NULL;
 }
 
 }  // namespace ash