CompositingReasonFinder should use a virtual function instead of a nest of branches

Source/core/rendering/RenderVideo.cpp

Index: Source/core/rendering/RenderVideo.cpp
diff --git a/Source/core/rendering/RenderVideo.cpp b/Source/core/rendering/RenderVideo.cpp
index 1f9d928f6a8d8dc7e21b3f4e5e67c7295cd8b5ed..e6ca53a7d911dad74952f5644a141cb671abadfb 100644
--- a/Source/core/rendering/RenderVideo.cpp
+++ b/Source/core/rendering/RenderVideo.cpp
@@ -276,4 +276,18 @@ LayoutUnit RenderVideo::offsetHeight() const
     return RenderMedia::offsetHeight();
 }
 
+CompositingReasons RenderVideo::additionalCompositingReasons(CompositingTriggerFlags triggers) const
+{
+    if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled()) {
+        HTMLMediaElement* media = toHTMLMediaElement(node());
+        if (media->isFullscreen())
+            return CompositingReasonVideo;
+    }
+
+    if ((triggers & VideoTrigger) && shouldDisplayVideo() && supportsAcceleratedRendering())
+        return CompositingReasonVideo;
+
+    return CompositingReasonNone;
+}
+
 } // namespace WebCore