[ScreenOrientation] Merge mojo interface ScreenOrientationListener into ScreenOrientation

third_party/WebKit/Source/modules/screen_orientation/ScreenOrientationDispatcher.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 ScreenOrientationDispatcher_h
-#define ScreenOrientationDispatcher_h
-
-#include "core/frame/PlatformEventDispatcher.h"
-#include "platform/heap/Handle.h"
-
-namespace blink {
-
-// ScreenOrientationDispatcher is a singleton that handles whether the current
-// Blink instance should be listening to the screen orientation platform events.
-// It is not a common implementation of PlatformEventDispatcher in the sense
-// that it doesn't actually dispatch events but simply start/stop listening. The
-// reason being that screen orientation events are always sent to the WebFrame's
-// but some platforms require to poll to have an accurate reporting. When
-// ScreenOrientationDispatcher is listening, that means that the platform should
-// be polling if required.
-class ScreenOrientationDispatcher final
-    : public GarbageCollected<ScreenOrientationDispatcher>,
-      public PlatformEventDispatcher {
-  USING_GARBAGE_COLLECTED_MIXIN(ScreenOrientationDispatcher);
-
- public:
-  static ScreenOrientationDispatcher& instance();
-
-  DECLARE_VIRTUAL_TRACE();
-
- private:
-  ScreenOrientationDispatcher();
-
-  // Inherited from PlatformEventDispatcher.
-  void startListening() override;
-  void stopListening() override;
-};
-
-}  // namespace blink
-
-#endif  // ScreenOrientationDispatcher_h