Extract content dependency from keyboard code

ash/test/content/keyboard_controller_proxy_stub.h

-// Copyright 2013 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.
-
-#ifndef ASH_TEST_CONTENT_KEYBOARD_CONTROLLER_PROXY_STUB_H_
-#define ASH_TEST_CONTENT_KEYBOARD_CONTROLLER_PROXY_STUB_H_
-
-#include "ui/aura/test/test_window_delegate.h"
-#include "ui/keyboard/keyboard_controller_proxy.h"
-
-namespace aura {
-class Window;
-}  // namespace aura
-
-namespace ash {
-
-// Stub implementation of KeyboardControllerProxy
-class KeyboardControllerProxyStub : public keyboard::KeyboardControllerProxy {
- public:
-  KeyboardControllerProxyStub();
-  ~KeyboardControllerProxyStub() override;
-
-  bool HasKeyboardWindow() const override;
-  aura::Window* GetKeyboardWindow() override;
-
- private:
-  // Overridden from keyboard::KeyboardControllerProxy:
-  ui::InputMethod* GetInputMethod() override;
-  void RequestAudioInput(
-      content::WebContents* web_contents,
-      const content::MediaStreamRequest& request,
-      const content::MediaResponseCallback& callback) override;
-  void LoadSystemKeyboard() override;
-  void ReloadKeyboardIfNeeded() override;
-
-  aura::test::TestWindowDelegate delegate_;
-  scoped_ptr<aura::Window> keyboard_;
-  DISALLOW_COPY_AND_ASSIGN(KeyboardControllerProxyStub);
-};
-
-}  // namespace ash
-
-#endif  // ASH_TEST_CONTENT_KEYBOARD_CONTROLLER_PROXY_STUB_H_