Track intersection of HTMLMediaElement with root frame.

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

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
index 3e66e714d787c2019aa964c29ced7d6b6d426afb..607cbde1bd8e8cbb527eed1fdd5e6755e978272b 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
@@ -4033,7 +4033,7 @@ void HTMLMediaElement::checkViewportIntersectionChanged() {
   // TODO(xjz): Early return if we not in tab mirroring.
 
   IntersectionGeometry geometry(
-      &document(), this, Vector<Length>(),
+      document().frame()->localFrameRoot()->document(), this, Vector<Length>(),
       IntersectionGeometry::ReportRootBounds::kShouldReportRootBounds);
   geometry.computeGeometry();
   IntRect intersectRect = geometry.intersectionIntRect();