Bustage fix for bug 759275 (Specialize unwrapping to HTML elements in dom bindings). r=bz.

--HG--
extra : rebase_source : 61cf7b76955aa08aa6509b77f0a85a35dd782a21

js/xpconnect/src/XPCQuickStubs.h

@@ -496,7 +496,7 @@ inline nsresult
 xpc_qsUnwrapArg(JSContext *cx, jsval v, Interface **ppArg,
                 StrongRefType **ppArgRef, jsval *vp)
 {
-    nsISupports* argRef;
+    nsISupports* argRef = *ppArgRef;
     nsresult rv = xpc_qsUnwrapArgImpl(cx, v, NS_GET_TEMPLATE_IID(Interface),
                                       reinterpret_cast<void **>(ppArg), &argRef,
                                       vp);

js/xpconnect/src/nsDOMQS.h

@@ -167,7 +167,7 @@ inline nsresult                                                               \
 xpc_qsUnwrapArg<_clazz>(JSContext *cx, jsval v, _clazz **ppArg,               \
                         _clazz **ppArgRef, jsval *vp)                         \
 {                                                                             \
-    nsISupports* argRef;                                                      \
+    nsISupports* argRef = static_cast<nsIContent*>(*ppArgRef);                \
     nsresult rv = xpc_qsUnwrapArg<_clazz>(cx, v, ppArg, &argRef, vp);         \
     *ppArgRef = static_cast<_clazz*>(static_cast<nsIContent*>(argRef));       \
     return rv;                                                                \