[Blink>Media] Add heuristic for dominant video detection for Android

third_party/WebKit/Source/core/html/MediaCustomControlsFullscreenDetector.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 MediaCustomControlsFullscreenDetector_h
+#define MediaCustomControlsFullscreenDetector_h
+
+#include "core/CoreExport.h"
+#include "core/events/EventListener.h"
+#include "platform/Timer.h"
+
+namespace blink {
+
+class Document;
+class HTMLVideoElement;
+class IntRect;
+class TimerBase;
+
+class CORE_EXPORT MediaCustomControlsFullscreenDetector final
+    : public EventListener {
+ public:
+  explicit MediaCustomControlsFullscreenDetector(HTMLVideoElement&);
+
+  // EventListener implementation.
+  bool operator==(const EventListener&) const override;
+
+  HTMLVideoElement& videoElement() { return *m_videoElement; }
+
+  void didMoveToNewDocument(Document& oldDocument);
+
+  DECLARE_VIRTUAL_TRACE();
+
+ private:
+  friend class MediaCustomControlsFullscreenDetectorTest;
+
+  // EventListener implementation.
+  void handleEvent(ExecutionContext*, Event*) override;
+
+  bool onEnterFullscreen();
+  bool onExitFullscreen();
+
+  void onCheckViewportIntersectionTimerFired(TimerBase*);
+
+  bool isVideoOrParentFullscreen();
+
+  static bool computeIsDominantVideo(const IntRect& targetRect,
+                                     const IntRect& rootRect,
+                                     const IntRect& intersectionRect);
+
+  // `m_videoElement` owns |this|.
+  Member<HTMLVideoElement> m_videoElement;
+  TaskRunnerTimer<MediaCustomControlsFullscreenDetector>
+      m_checkViewportIntersectionTimer;
+};
+
+}  // namespace blink
+
+#endif  // MediaCustomControlsFullscreenDetector_h