media_controls: Add UI for showing a promo bubble on a control button.

third_party/WebKit/Source/modules/media_controls/elements/MediaControlButtonPromoElements.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 MediaControlButtonPromoElements_h
+#define MediaControlButtonPromoElements_h
+
+#include "core/html/shadow/MediaControlElementTypes.h"
+
+namespace blink {
+class MediaControlsImpl;
+
+class MediaControlButtonPromoAnimation final : public MediaControlDivElement {
+ public:
+  explicit MediaControlButtonPromoAnimation(MediaControlsImpl&);
+};
+
+class MediaControlButtonPromoArrow final : public MediaControlDivElement {
+ public:
+  explicit MediaControlButtonPromoArrow(MediaControlsImpl&);
+};
+
+class MediaControlButtonPromoText final : public MediaControlDivElement {
+ public:
+  explicit MediaControlButtonPromoText(MediaControlsImpl&,
+                                       MediaControlElementType,
+                                       WebLocalizedString::Name);
+};
+
+class MediaControlButtonPromoContainer final : public MediaControlDivElement {
+ public:
+  explicit MediaControlButtonPromoContainer(MediaControlsImpl&,
+                                            MediaControlElementType,
+                                            WebLocalizedString::Name);
+
+  DECLARE_VIRTUAL_TRACE();
+
+ private:
+  Member<MediaControlButtonPromoAnimation> animation_;
+  Member<MediaControlButtonPromoArrow> arrow_;
+  Member<MediaControlButtonPromoText> text_;
+};
+
+}  // namespace blink
+
+#endif  // MediaControlButtonPromoElements_h