Detect change on the intersection of video and viewport.

third_party/WebKit/public/platform/WebMediaPlayer.h

Index: third_party/WebKit/public/platform/WebMediaPlayer.h
diff --git a/third_party/WebKit/public/platform/WebMediaPlayer.h b/third_party/WebKit/public/platform/WebMediaPlayer.h
index 75db1339d060c067c15e633cd2baa69f5af61843..68f36fd918d9431654dcef64e95ff65d5d30008e 100644
--- a/third_party/WebKit/public/platform/WebMediaPlayer.h
+++ b/third_party/WebKit/public/platform/WebMediaPlayer.h
@@ -35,6 +35,7 @@
 #include "WebCanvas.h"
 #include "WebContentDecryptionModule.h"
 #include "WebMediaSource.h"
+#include "WebRect.h"
 #include "WebSetSinkIdCallbacks.h"
 #include "WebString.h"
 
@@ -54,7 +55,6 @@ class WebMediaPlayerSource;
 class WebSecurityOrigin;
 class WebString;
 class WebURL;
-struct WebRect;
 struct WebSize;
 
 class WebMediaPlayer {
@@ -105,6 +105,14 @@ class WebMediaPlayer {
   typedef WebString TrackId;
   enum TrackType { TextTrack, AudioTrack, VideoTrack };
 
+  struct ViewportIntersectionInfo {
+    ViewportIntersectionInfo() {}
+    ~ViewportIntersectionInfo() {}
+
+    WebRect rootRect;
+    WebRect intersectRect;
+  };
+
   virtual ~WebMediaPlayer() {}
 
   virtual void load(LoadType, const WebMediaPlayerSource&, CORSMode) = 0;
@@ -228,6 +236,11 @@ class WebMediaPlayer {
   virtual void enteredFullscreen() {}
   virtual void exitedFullscreen() {}
 
+  // Inform WebMediaPlayer when the intersection of the media element and
+  // viewport changes.
+  virtual void viewportIntersectionChanged(
+      const ViewportIntersectionInfo& info) {}
+
   virtual void enabledAudioTracksChanged(
       const WebVector<TrackId>& enabledTrackIds) {}
   // |selectedTrackId| is null if no track is selected.