Merge 147281 "Cross-Origin copy&paste / drag&drop allowing XSS v..."

Source/WebCore/html/HTMLFrameElementBase.cpp

Index: Source/WebCore/html/HTMLFrameElementBase.cpp
===================================================================
--- Source/WebCore/html/HTMLFrameElementBase.cpp	(revision 148876)
+++ Source/WebCore/html/HTMLFrameElementBase.cpp	(working copy)
@@ -222,6 +222,11 @@
     return attribute.name() == srcAttr || HTMLFrameOwnerElement::isURLAttribute(attribute);
 }
 
+bool HTMLFrameElementBase::isHTMLContentAttribute(const Attribute& attribute) const
+{
+    return attribute.name() == srcdocAttr || HTMLFrameOwnerElement::isHTMLContentAttribute(attribute);
+}
+
 int HTMLFrameElementBase::width()
 {
     document()->updateLayoutIgnorePendingStylesheets();