Monitor the intersection of video and viewport.

third_party/WebKit/Source/web/FrameLoaderClientImpl.cpp

Index: third_party/WebKit/Source/web/FrameLoaderClientImpl.cpp
diff --git a/third_party/WebKit/Source/web/FrameLoaderClientImpl.cpp b/third_party/WebKit/Source/web/FrameLoaderClientImpl.cpp
index ff994e85e97eb275ddb33af0cbeefa75f962e9d5..338f7758e2ad2cadcfddd5f5750184329ae2cf0a 100644
--- a/third_party/WebKit/Source/web/FrameLoaderClientImpl.cpp
+++ b/third_party/WebKit/Source/web/FrameLoaderClientImpl.cpp
@@ -773,9 +773,14 @@ std::unique_ptr<WebMediaPlayer> FrameLoaderClientImpl::createWebMediaPlayer(
   HTMLMediaElementEncryptedMedia& encryptedMedia =
       HTMLMediaElementEncryptedMedia::from(htmlMediaElement);
   WebString sinkId(HTMLMediaElementAudioOutputDevice::sinkId(htmlMediaElement));
-  return wrapUnique(webFrame->client()->createMediaPlayer(
-      source, client, &encryptedMedia, encryptedMedia.contentDecryptionModule(),
-      sinkId));
+  std::unique_ptr<WebMediaPlayer> mediaPlayer =
+      wrapUnique(webFrame->client()->createMediaPlayer(
+          source, client, &encryptedMedia,
+          encryptedMedia.contentDecryptionModule(), sinkId));
+  float ratio = htmlMediaElement.videoViewportRatio();
+  if (ratio)
+    mediaPlayer->videoViewportRatioChanged(ratio);
+  return mediaPlayer;
 }
 
 ObjectContentType FrameLoaderClientImpl::getObjectContentType(