--- a/browser/installer/package-manifest.in
+++ b/browser/installer/package-manifest.in
@@ -436,17 +436,16 @@
 @BINPATH@/components/nsUpdateService.manifest
 @BINPATH@/components/nsUpdateService.js
 @BINPATH@/components/nsUpdateServiceStub.js
 #endif
 @BINPATH@/components/nsUpdateTimerManager.manifest
 @BINPATH@/components/nsUpdateTimerManager.js
 @BINPATH@/components/addoncompat.manifest
 @BINPATH@/components/multiprocessShims.js
-@BINPATH@/components/remoteTagService.js
 @BINPATH@/components/pluginGlue.manifest
 @BINPATH@/components/ProcessSingleton.manifest
 @BINPATH@/components/MainProcessSingleton.js
 @BINPATH@/components/ContentProcessSingleton.js
 @BINPATH@/browser/components/nsSessionStore.manifest
 @BINPATH@/browser/components/nsSessionStartup.js
 @BINPATH@/browser/components/nsSessionStore.js
 @BINPATH@/components/nsURLFormatter.manifest

--- a/js/ipc/JavaScriptTypes.ipdlh
+++ b/js/ipc/JavaScriptTypes.ipdlh
@@ -32,17 +32,16 @@ struct LocalObject
     uint64_t serializedId;
 };
 
 struct RemoteObject
 {
     uint64_t serializedId;
     bool isCallable;
     bool isConstructor;
-    nsCString objectTag;
 };
 
 union ObjectVariant
 {
     LocalObject;
     RemoteObject;
 };
 

--- a/js/ipc/WrapperOwner.cpp
+++ b/js/ipc/WrapperOwner.cpp
@@ -8,38 +8,31 @@
 #include "WrapperOwner.h"
 #include "JavaScriptLogging.h"
 #include "mozilla/unused.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "jsfriendapi.h"
 #include "xpcprivate.h"
 #include "WrapperFactory.h"
 
-#include "nsIRemoteTagService.h"
-
 using namespace js;
 using namespace JS;
 using namespace mozilla;
 using namespace mozilla::jsipc;
 
 struct AuxCPOWData
 {
     ObjectId id;
     bool isCallable;
     bool isConstructor;
 
-    // The object tag is just some auxilliary information that clients can use
-    // however they see fit.
-    nsCString objectTag;
-
-    AuxCPOWData(ObjectId id, bool isCallable, bool isConstructor, const nsACString &objectTag)
+    AuxCPOWData(ObjectId id, bool isCallable, bool isConstructor)
       : id(id),
         isCallable(isCallable),
-        isConstructor(isConstructor),
-        objectTag(objectTag)
+        isConstructor(isConstructor)
     {}
 };
 
 WrapperOwner::WrapperOwner(JSRuntime *rt)
   : JavaScriptShared(rt),
     inactive_(false)
 {
 }
@@ -805,27 +798,16 @@ bool
 IsWrappedCPOW(JSObject *obj)
 {
     JSObject *unwrapped = js::UncheckedUnwrap(obj, true);
     if (!unwrapped)
         return false;
     return IsCPOW(unwrapped);
 }
 
-void
-GetWrappedCPOWTag(JSObject *obj, nsACString &out)
-{
-    JSObject *unwrapped = js::UncheckedUnwrap(obj, true);
-    MOZ_ASSERT(IsCPOW(unwrapped));
-
-    AuxCPOWData *aux = AuxCPOWDataOf(unwrapped);
-    if (aux)
-        out = aux->objectTag;
-}
-
 nsresult
 InstanceOf(JSObject *proxy, const nsID *id, bool *bp)
 {
     WrapperOwner *parent = OwnerOf(proxy);
     if (!parent->active())
         return NS_ERROR_UNEXPECTED;
     return parent->instanceOf(proxy, id, bp);
 }
@@ -897,31 +879,19 @@ WrapperOwner::ok(JSContext *cx, const Re
     if (!fromVariant(cx, status.get_ReturnException().exn(), &exn))
         return false;
 
     JS_SetPendingException(cx, exn);
     return false;
 }
 
 static RemoteObject
-MakeRemoteObject(JSContext *cx, ObjectId id, HandleObject obj)
+MakeRemoteObject(ObjectId id, JSObject *obj)
 {
-    nsCString objectTag;
-
-    nsCOMPtr<nsIRemoteTagService> service =
-        do_GetService("@mozilla.org/addons/remote-tag-service;1");
-    if (service) {
-        RootedValue objVal(cx, ObjectValue(*obj));
-        service->GetRemoteObjectTag(objVal, objectTag);
-    }
-
-    return RemoteObject(id.serialize(),
-                        JS::IsCallable(obj),
-                        JS::IsConstructor(obj),
-                        objectTag);
+    return RemoteObject(id.serialize(), JS::IsCallable(obj), JS::IsConstructor(obj));
 }
 
 bool
 WrapperOwner::toObjectVariant(JSContext *cx, JSObject *objArg, ObjectVariant *objVarp)
 {
     RootedObject obj(cx, objArg);
     MOZ_ASSERT(obj);
 
@@ -935,32 +905,32 @@ WrapperOwner::toObjectVariant(JSContext 
         *objVarp = LocalObject(idOf(obj).serialize());
         return true;
     }
     bool waiveXray = wrapperFlags & xpc::WrapperFactory::WAIVE_XRAY_WRAPPER_FLAG;
 
     ObjectId id = objectIdMap(waiveXray).find(obj);
     if (!id.isNull()) {
         MOZ_ASSERT(id.hasXrayWaiver() == waiveXray);
-        *objVarp = MakeRemoteObject(cx, id, obj);
+        *objVarp = MakeRemoteObject(id, obj);
         return true;
     }
 
     // Need to call PreserveWrapper on |obj| in case it's a reflector.
     // FIXME: What if it's an XPCWrappedNative?
     if (mozilla::dom::IsDOMObject(obj))
         mozilla::dom::TryPreserveWrapper(obj);
 
     id = ObjectId(nextSerialNumber_++, waiveXray);
     if (!objects_.add(id, obj))
         return false;
     if (!objectIdMap(waiveXray).add(cx, obj, id))
         return false;
 
-    *objVarp = MakeRemoteObject(cx, id, obj);
+    *objVarp = MakeRemoteObject(id, obj);
     return true;
 }
 
 JSObject *
 WrapperOwner::fromObjectVariant(JSContext *cx, ObjectVariant objVar)
 {
     if (objVar.type() == ObjectVariant::TRemoteObject) {
         return fromRemoteObjectVariant(cx, objVar.get_RemoteObject());
@@ -989,20 +959,17 @@ WrapperOwner::fromRemoteObjectVariant(JS
             return nullptr;
 
         if (!cpows_.add(objId, obj))
             return nullptr;
 
         // Incref once we know the decref will be called.
         incref();
 
-        AuxCPOWData *aux = new AuxCPOWData(objId,
-                                           objVar.isCallable(),
-                                           objVar.isConstructor(),
-                                           objVar.objectTag());
+        AuxCPOWData *aux = new AuxCPOWData(objId, objVar.isCallable(), objVar.isConstructor());
 
         SetProxyExtra(obj, 0, PrivateValue(this));
         SetProxyExtra(obj, 1, PrivateValue(aux));
     }
 
     if (!JS_WrapObject(cx, &obj))
         return nullptr;
     return obj;

--- a/js/ipc/WrapperOwner.h
+++ b/js/ipc/WrapperOwner.h
@@ -158,15 +158,12 @@ bool
 IsWrappedCPOW(JSObject *obj);
 
 nsresult
 InstanceOf(JSObject *obj, const nsID *id, bool *bp);
 
 bool
 DOMInstanceOf(JSContext *cx, JSObject *obj, int prototypeID, int depth, bool *bp);
 
-void
-GetWrappedCPOWTag(JSObject *obj, nsACString &out);
-
 } // jsipc
 } // mozilla
 
 #endif // mozilla_jsipc_WrapperOwner_h__

--- a/js/xpconnect/idl/moz.build
+++ b/js/xpconnect/idl/moz.build
@@ -3,17 +3,16 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 XPIDL_SOURCES += [
     'mozIJSSubScriptLoader.idl',
     'nsIAddonInterposition.idl',
     'nsIJSRuntimeService.idl',
-    'nsIRemoteTagService.idl',
     'nsIScriptError.idl',
     'nsIXPConnect.idl',
     'nsIXPCScriptable.idl',
     'xpccomponents.idl',
     'xpcexception.idl',
     'xpcIJSGetFactory.idl',
     'xpcIJSModuleLoader.idl',
     'xpcIJSWeakReference.idl',

deleted file mode 100644
--- a/js/xpconnect/idl/nsIRemoteTagService.idl
+++ /dev/null
@@ -1,13 +0,0 @@
-/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "nsISupports.idl"
-
-[scriptable,uuid(59dbe3d0-6084-11e4-9803-0800200c9a66)]
-interface nsIRemoteTagService : nsISupports
-{
-    ACString getRemoteObjectTag(in jsval target);
-};

--- a/js/xpconnect/idl/xpccomponents.idl
+++ b/js/xpconnect/idl/xpccomponents.idl
@@ -117,17 +117,17 @@ interface nsIXPCComponents_utils_Sandbox
 interface ScheduledGCCallback : nsISupports
 {
     void callback();
 };
 
 /**
 * interface of Components.utils
 */
-[scriptable, uuid(2617a800-63c1-11e4-9803-0800200c9a66)]
+[scriptable, uuid(ad41689c-ed0e-4a92-8f19-a53c2dba5711)]
 interface nsIXPCComponents_Utils : nsISupports
 {
 
     /* reportError is designed to be called from JavaScript only.
      *
      * It will report a JS Error object to the JS console, and return. It
      * is meant for use in exception handler blocks which want to "eat"
      * an exception, but still want to report it to the console.
@@ -430,25 +430,16 @@ interface nsIXPCComponents_Utils : nsISu
      */
     bool isDeadWrapper(in jsval obj);
 
     /**
      * Determines whether this object is a cross-process wrapper.
      */
     bool isCrossProcessWrapper(in jsval obj);
 
-    /**
-     * CPOWs can have user data attached to them. This data originates
-     * in the local process via the
-     * nsIRemoteTagService.getRemoteObjectTag method. It's sent along
-     * with the CPOW to the remote process, where it can be fetched
-     * with this function, getCrossProcessWrapperTag.
-     */
-    ACString getCrossProcessWrapperTag(in jsval obj);
-
     /*
      * To be called from JS only. This is for Gecko internal use only, and may
      * disappear at any moment.
      *
      * Forces a recomputation of all wrappers in and out of the compartment
      * containing |vobj|. If |vobj| is not an object, all wrappers system-wide
      * are recomputed.
      */

--- a/js/xpconnect/src/XPCComponents.cpp
+++ b/js/xpconnect/src/XPCComponents.cpp
@@ -3101,26 +3101,16 @@ nsXPCComponents_Utils::IsCrossProcessWra
     *out = false;
     if (obj.isPrimitive())
         return NS_ERROR_INVALID_ARG;
 
     *out = jsipc::IsWrappedCPOW(&obj.toObject());
     return NS_OK;
 }
 
-NS_IMETHODIMP
-nsXPCComponents_Utils::GetCrossProcessWrapperTag(HandleValue obj, nsACString &out)
-{
-    if (obj.isPrimitive() || !jsipc::IsWrappedCPOW(&obj.toObject()))
-        return NS_ERROR_INVALID_ARG;
-
-    jsipc::GetWrappedCPOWTag(&obj.toObject(), out);
-    return NS_OK;
-}
-
 /* void recomputerWrappers(jsval vobj); */
 NS_IMETHODIMP
 nsXPCComponents_Utils::RecomputeWrappers(HandleValue vobj, JSContext *cx)
 {
     // Determine the compartment of the given object, if any.
     JSCompartment *c = vobj.isObject()
                        ? js::GetObjectCompartment(js::UncheckedUnwrap(&vobj.toObject()))
                        : nullptr;

--- a/toolkit/components/addoncompat/addoncompat.manifest
+++ b/toolkit/components/addoncompat/addoncompat.manifest
@@ -1,4 +1,2 @@
 component {1363d5f0-d95e-11e3-9c1a-0800200c9a66} multiprocessShims.js
 contract @mozilla.org/addons/multiprocess-shims;1 {1363d5f0-d95e-11e3-9c1a-0800200c9a66}
-component {dfd07380-6083-11e4-9803-0800200c9a66} remoteTagService.js
-contract @mozilla.org/addons/remote-tag-service;1 {dfd07380-6083-11e4-9803-0800200c9a66}

--- a/toolkit/components/addoncompat/moz.build
+++ b/toolkit/components/addoncompat/moz.build
@@ -4,15 +4,14 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 TEST_DIRS += ['tests']
 
 EXTRA_COMPONENTS += [
     'addoncompat.manifest',
     'multiprocessShims.js',
-    'remoteTagService.js',
 ]
 
 EXTRA_JS_MODULES += [
     'RemoteAddonsChild.jsm',
     'RemoteAddonsParent.jsm',
 ]

--- a/toolkit/components/addoncompat/multiprocessShims.js
+++ b/toolkit/components/addoncompat/multiprocessShims.js
@@ -72,17 +72,23 @@ function AddonInterpositionService()
 AddonInterpositionService.prototype = {
   classID: Components.ID("{1363d5f0-d95e-11e3-9c1a-0800200c9a66}"),
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIAddonInterposition, Ci.nsISupportsWeakReference]),
 
   // When the interface is not known for a method call, this code
   // determines the type of the target object.
   getObjectTag: function(target) {
     if (Cu.isCrossProcessWrapper(target)) {
-      return Cu.getCrossProcessWrapperTag(target);
+      if (target instanceof Ci.nsIDocShellTreeItem) {
+        return "ContentDocShellTreeItem";
+      }
+
+      if (target instanceof Ci.nsIDOMDocument) {
+        return "ContentDocument";
+      }
     }
 
     const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
     if (target instanceof Ci.nsIDOMXULElement) {
       if (target.localName == "browser" && target.isRemoteBrowser) {
         return "RemoteBrowserElement";
       }
 

deleted file mode 100644
--- a/toolkit/components/addoncompat/remoteTagService.js
+++ /dev/null
@@ -1,39 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-"use strict";
-
-const Cu = Components.utils;
-const Ci = Components.interfaces;
-
-Cu.import("resource://gre/modules/XPCOMUtils.jsm");
-
-function RemoteTagServiceService()
-{
-}
-
-RemoteTagServiceService.prototype = {
-  classID: Components.ID("{dfd07380-6083-11e4-9803-0800200c9a66}"),
-  QueryInterface: XPCOMUtils.generateQI([Ci.nsIRemoteTagService, Ci.nsISupportsWeakReference]),
-
-  /**
-   * CPOWs can have user data attached to them. This data originates
-   * in the local process from this function, getRemoteObjectTag. It's
-   * sent along with the CPOW to the remote process, where it can be
-   * fetched with Components.utils.getCrossProcessWrapperTag.
-   */
-  getRemoteObjectTag: function(target) {
-    if (target instanceof Ci.nsIDocShellTreeItem) {
-      return "ContentDocShellTreeItem";
-    }
-
-    if (target instanceof Ci.nsIDOMDocument) {
-      return "ContentDocument";
-    }
-
-    return "generic";
-  }
-};
-
-this.NSGetFactory = XPCOMUtils.generateNSGetFactory([RemoteTagServiceService]);