Remove the keyboard from the browser demo.

examples/keyboard/keyboard_delegate.h

-// Copyright 2014 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 EXAMPLES_KEYBOARD_KEYBOARD_DELEGATE_H_
-#define EXAMPLES_KEYBOARD_KEYBOARD_DELEGATE_H_
-
-#include "base/basictypes.h"
-
-namespace mojo {
-namespace examples {
-
-class KeyboardDelegate {
- public:
-  KeyboardDelegate() {}
-
-  virtual void OnKeyPressed(int key_code, int event_flags) = 0;
-
- protected:
-  virtual ~KeyboardDelegate() {}
-};
-
-}  // namespace examples
-}  // namespace mojo
-
-#endif  // EXAMPLES_KEYBOARD_KEYBOARD_DELEGATE_H_