--- a/js/xpconnect/idl/nsIXPConnect.idl
+++ b/js/xpconnect/idl/nsIXPConnect.idl
@@ -399,26 +399,16 @@ interface nsIXPConnect : nsISupports
     wrapJSAggregatedToNative(in nsISupports  aOuter,
                              in JSContextPtr aJSContext,
                              in JSObjectPtr  aJSObj,
                              in nsIIDRef     aIID,
                              [iid_is(aIID),retval] out nsQIResult result);
 
     // Methods added since mozilla 0.6....
 
-    /**
-    * This only succeeds if the native object is already wrapped by xpconnect.
-    * A new wrapper is *never* constructed.
-    */
-    nsIXPConnectWrappedNative
-    getWrappedNativeOfNativeObject(in JSContextPtr aJSContext,
-                                   in JSObjectPtr  aScope,
-                                   in nsISupports  aCOMObj,
-                                   in nsIIDRef     aIID);
-
     void
     setFunctionThisTranslator(in nsIIDRef aIID,
                               in nsIXPCFunctionThisTranslator aTranslator);
 
     JSObjectPtr
     getWrappedNativePrototype(in JSContextPtr aJSContext,
                               in JSObjectPtr  aScope,
                               in nsIClassInfo aClassInfo);

--- a/js/xpconnect/src/XPCWrappedNative.cpp
+++ b/js/xpconnect/src/XPCWrappedNative.cpp
@@ -474,64 +474,16 @@ FinishCreate(XPCWrappedNativeScope* Scop
             cache->SetWrapper(flat);
     }
 
     DEBUG_CheckClassInfoClaims(wrapper);
     wrapper.forget(resultWrapper);
     return NS_OK;
 }
 
-// static
-nsresult
-XPCWrappedNative::GetUsedOnly(nsISupports* Object,
-                              XPCWrappedNativeScope* Scope,
-                              XPCNativeInterface* Interface,
-                              XPCWrappedNative** resultWrapper)
-{
-    AutoJSContext cx;
-    MOZ_ASSERT(Object, "XPCWrappedNative::GetUsedOnly was called with a null Object");
-    MOZ_ASSERT(Interface);
-
-    RefPtr<XPCWrappedNative> wrapper;
-    nsWrapperCache* cache = nullptr;
-    CallQueryInterface(Object, &cache);
-    if (cache) {
-        RootedObject flat(cx, cache->GetWrapper());
-        if (!flat) {
-            *resultWrapper = nullptr;
-            return NS_OK;
-        }
-        wrapper = XPCWrappedNative::Get(flat);
-    } else {
-        nsCOMPtr<nsISupports> identity = do_QueryInterface(Object);
-
-        if (!identity) {
-            NS_ERROR("This XPCOM object fails in QueryInterface to nsISupports!");
-            return NS_ERROR_FAILURE;
-        }
-
-        Native2WrappedNativeMap* map = Scope->GetWrappedNativeMap();
-
-        wrapper = map->Find(identity);
-        if (!wrapper) {
-            *resultWrapper = nullptr;
-            return NS_OK;
-        }
-    }
-
-    nsresult rv;
-    if (!wrapper->FindTearOff(Interface, false, &rv)) {
-        MOZ_ASSERT(NS_FAILED(rv), "returning NS_OK on failure");
-        return rv;
-    }
-
-    wrapper.forget(resultWrapper);
-    return NS_OK;
-}
-
 // This ctor is used if this object will have a proto.
 XPCWrappedNative::XPCWrappedNative(already_AddRefed<nsISupports>&& aIdentity,
                                    XPCWrappedNativeProto* aProto)
     : mMaybeProto(aProto),
       mSet(aProto->GetSet())
 {
     MOZ_ASSERT(NS_IsMainThread());
 

--- a/js/xpconnect/src/nsXPConnect.cpp
+++ b/js/xpconnect/src/nsXPConnect.cpp
@@ -764,50 +764,16 @@ xpc::UnwrapReflectorToISupports(JSObject
     // this if non-null our thing will definitely be a DOM object, and we know
     // their QI to nsISupports doesn't do anything weird.
     nsCOMPtr<nsISupports> canonical =
         do_QueryInterface(mozilla::dom::UnwrapDOMObjectToISupports(reflector));
     return canonical.forget();
 }
 
 NS_IMETHODIMP
-nsXPConnect::GetWrappedNativeOfNativeObject(JSContext * aJSContext,
-                                            JSObject * aScopeArg,
-                                            nsISupports* aCOMObj,
-                                            const nsIID & aIID,
-                                            nsIXPConnectWrappedNative** _retval)
-{
-    MOZ_ASSERT(aJSContext, "bad param");
-    MOZ_ASSERT(aScopeArg, "bad param");
-    MOZ_ASSERT(aCOMObj, "bad param");
-    MOZ_ASSERT(_retval, "bad param");
-
-    *_retval = nullptr;
-
-    RootedObject aScope(aJSContext, aScopeArg);
-
-    XPCWrappedNativeScope* scope = ObjectScope(aScope);
-    if (!scope)
-        return UnexpectedFailure(NS_ERROR_FAILURE);
-
-    RefPtr<XPCNativeInterface> iface =
-        XPCNativeInterface::GetNewOrUsed(&aIID);
-    if (!iface)
-        return NS_ERROR_FAILURE;
-
-    XPCWrappedNative* wrapper;
-
-    nsresult rv = XPCWrappedNative::GetUsedOnly(aCOMObj, scope, iface, &wrapper);
-    if (NS_FAILED(rv))
-        return NS_ERROR_FAILURE;
-    *_retval = static_cast<nsIXPConnectWrappedNative*>(wrapper);
-    return NS_OK;
-}
-
-NS_IMETHODIMP
 nsXPConnect::SetFunctionThisTranslator(const nsIID & aIID,
                                        nsIXPCFunctionThisTranslator* aTranslator)
 {
     XPCJSRuntime* rt = GetRuntimeInstance();
     IID2ThisTranslatorMap* map = rt->GetThisTranslatorMap();
     map->Add(aIID, aTranslator);
     return NS_OK;
 }

--- a/js/xpconnect/src/xpcprivate.h
+++ b/js/xpconnect/src/xpcprivate.h
@@ -1646,22 +1646,16 @@ public:
                   XPCWrappedNative** wrappedGlobal);
 
     static nsresult
     GetNewOrUsed(xpcObjectHelper& helper,
                  XPCWrappedNativeScope* Scope,
                  XPCNativeInterface* Interface,
                  XPCWrappedNative** wrapper);
 
-    static nsresult
-    GetUsedOnly(nsISupports* Object,
-                XPCWrappedNativeScope* Scope,
-                XPCNativeInterface* Interface,
-                XPCWrappedNative** wrapper);
-
     void FlatJSObjectFinalized();
     void FlatJSObjectMoved(JSObject* obj, const JSObject* old);
 
     void SystemIsBeingShutDown();
 
     enum CallMode {CALL_METHOD, CALL_GETTER, CALL_SETTER};
 
     static bool CallMethod(XPCCallContext& ccx,