Media Controls: move all MediaControlDivElement sub-classes to modules/.

third_party/WebKit/Source/modules/media_controls/elements/MediaControlElementsHelper.h

+// Copyright 2017 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 MediaControlElementsHelper_h
+#define MediaControlElementsHelper_h
+
+#include "platform/wtf/Allocator.h"
+
+namespace blink {
+
+class Event;
+
+// Helper class for media control elements. It contains methods, constants or
+// concepts shared by more than one element.
+class MediaControlElementsHelper final {
+  STATIC_ONLY(MediaControlElementsHelper);
+
+ public:
+  static bool IsUserInteractionEvent(Event*);
+};
+
+}  // namespace blink
+
+#endif  // MediaControlElementsHelper_h