Highlighting on UAOS - alternate approach

public/platform/WebLayer.h

Index: public/platform/WebLayer.h
diff --git a/public/platform/WebLayer.h b/public/platform/WebLayer.h
index 8a3e7cacdf01f4901f1b94409fef2ecb756e9d3c..b31dceba78e987281b93b3eea8a77d3e1e091ceb 100644
--- a/public/platform/WebLayer.h
+++ b/public/platform/WebLayer.h
@@ -168,6 +168,8 @@ public:
     // in the layer hierarchy.
     virtual void setScrollParent(WebLayer*) = 0;
 
+    virtual bool hasScrollChildren() = 0;
+
     // A layer will not respect any clips established by layers between it and
     // its nearest clipping ancestor. Note, the clip parent must be an ancestor.
     // This is not a requirement of the scroll parent.