Detect change on the intersection of video and viewport.

third_party/WebKit/Source/core/html/HTMLMediaElement.h

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.h
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.h b/third_party/WebKit/Source/core/html/HTMLMediaElement.h
index 0bd98bca6d30fa8ac49f065ddad4b715583cedbb..770d71cfe6b12e4a49836f1fb99698c5c2589687 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.h
@@ -312,6 +312,10 @@ class CORE_EXPORT HTMLMediaElement : public HTMLElement,
     return m_remotePlaybackClient;
   }
 
+  WebMediaPlayer::ViewportIntersectionInfo currentViewportIntersection() const {
+    return m_currentViewportIntersection;
+  }
+
  protected:
   HTMLMediaElement(const QualifiedName&, Document&);
   ~HTMLMediaElement() override;
@@ -731,6 +735,8 @@ class CORE_EXPORT HTMLMediaElement : public HTMLElement,
   // class AutoplayVisibilityObserver;
   Member<ElementVisibilityObserver> m_autoplayVisibilityObserver;
 
+  WebMediaPlayer::ViewportIntersectionInfo m_currentViewportIntersection;
+
   static URLRegistry* s_mediaStreamRegistry;
 };