Let the WebMediaPlayer decide whether to use overlay video.

Source/core/layout/LayoutVideo.cpp

Index: Source/core/layout/LayoutVideo.cpp
diff --git a/Source/core/layout/LayoutVideo.cpp b/Source/core/layout/LayoutVideo.cpp
index 85d2caa574f58ff732e200d320932b67d8fe021f..2c5a199d61c71904542538fc030cc8dbb1fe296e 100644
--- a/Source/core/layout/LayoutVideo.cpp
+++ b/Source/core/layout/LayoutVideo.cpp
@@ -246,11 +246,9 @@ LayoutUnit LayoutVideo::offsetHeight() const
 
 CompositingReasons LayoutVideo::additionalCompositingReasons() const
 {
-    if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled()) {
-        HTMLMediaElement* media = toHTMLMediaElement(node());
-        if (media->isFullscreen())
-            return CompositingReasonVideo;
-    }
+    HTMLMediaElement* element = toHTMLMediaElement(node());
+    if (element->isFullscreen() && element->supportsOverlayFullscreenVideo())
+        return CompositingReasonVideo;
 
     if (shouldDisplayVideo() && supportsAcceleratedRendering())
         return CompositingReasonVideo;