--- a/dom/bindings/Codegen.py
+++ b/dom/bindings/Codegen.py
@@ -8359,76 +8359,16 @@ class CGDOMJSProxyHandler_finalize(Class
     def __init__(self, descriptor):
         args = [Argument('JSFreeOp*', 'fop'), Argument('JSObject*', 'proxy')]
         ClassMethod.__init__(self, "finalize", "void", args)
         self.descriptor = descriptor
     def getBody(self):
         return ("%s self = UnwrapProxy(proxy);\n\n" % (self.descriptor.nativeType + "*") +
                 finalizeHook(self.descriptor, FINALIZE_HOOK_NAME, self.args[0].name).define())
 
-class CGDOMJSProxyHandler_getElementIfPresent(ClassMethod):
-    def __init__(self, descriptor):
-        args = [Argument('JSContext*', 'cx'),
-                Argument('JS::Handle<JSObject*>', 'proxy'),
-                Argument('JS::Handle<JSObject*>', 'receiver'),
-                Argument('uint32_t', 'index'),
-                Argument('JS::MutableHandle<JS::Value>', 'vp'),
-                Argument('bool*', 'present')]
-        ClassMethod.__init__(self, "getElementIfPresent", "bool", args)
-        self.descriptor = descriptor
-    def getBody(self):
-        successCode = ("*present = found;\n"
-                       "return true;")
-        templateValues = {'jsvalRef': 'vp', 'jsvalHandle': 'vp',
-                          'obj': 'proxy', 'successCode': successCode}
-        if self.descriptor.supportsIndexedProperties():
-            get = (CGProxyIndexedGetter(self.descriptor, templateValues).define() + "\n"
-                   "// We skip the expando object and any named getters if\n"
-                   "// there is an indexed getter.\n" +
-                   "\n") % (self.descriptor.nativeType)
-        else:
-            if self.descriptor.supportsNamedProperties():
-                get = CGProxyNamedGetter(self.descriptor, templateValues,
-                                         "UINT_TO_JSVAL(index)").define()
-            get += """
-
-JS::Rooted<JSObject*> expando(cx, GetExpandoObject(proxy));
-if (expando) {
-  bool isPresent;
-  if (!JS_GetElementIfPresent(cx, expando, index, expando, vp, &isPresent)) {
-    return false;
-  }
-  if (isPresent) {
-    *present = true;
-    return true;
-  }
-}
-"""
-
-        return """MOZ_ASSERT(!xpc::WrapperFactory::IsXrayWrapper(proxy),
-             "Should not have a XrayWrapper here");
-
-""" + get + """
-JS::Rooted<JSObject*> proto(cx);
-if (!js::GetObjectProto(cx, proxy, &proto)) {
-  return false;
-}
-if (proto) {
-  bool isPresent;
-  if (!JS_GetElementIfPresent(cx, proto, index, proxy, vp, &isPresent)) {
-    return false;
-  }
-  *present = isPresent;
-  return true;
-}
-
-*present = false;
-// Can't Debug_SetValueRangeToCrashOnTouch because it's not public
-return true;"""
-
 class CGDOMJSProxyHandler_getInstance(ClassMethod):
     def __init__(self):
         ClassMethod.__init__(self, "getInstance", "DOMProxyHandler*", [], static=True)
     def getBody(self):
         return """static DOMProxyHandler instance;
 return &instance;"""
 
 class CGDOMJSProxyHandler(CGClass):
@@ -8441,17 +8381,16 @@ class CGDOMJSProxyHandler(CGClass):
                    ClassUsingDeclaration("mozilla::dom::DOMProxyHandler",
                                          "defineProperty"),
                    CGDOMJSProxyHandler_getOwnPropertyNames(descriptor),
                    CGDOMJSProxyHandler_hasOwn(descriptor),
                    CGDOMJSProxyHandler_get(descriptor),
                    CGDOMJSProxyHandler_className(descriptor),
                    CGDOMJSProxyHandler_finalizeInBackground(descriptor),
                    CGDOMJSProxyHandler_finalize(descriptor),
-                   CGDOMJSProxyHandler_getElementIfPresent(descriptor),
                    CGDOMJSProxyHandler_getInstance(),
                    CGDOMJSProxyHandler_delete(descriptor)]
         CGClass.__init__(self, 'DOMProxyHandler',
                          bases=[ClassBase('mozilla::dom::DOMProxyHandler')],
                          constructors=constructors,
                          methods=methods)
 
 class CGDOMJSProxyHandlerDeclarer(CGThing):

--- a/js/public/Class.h
+++ b/js/public/Class.h
@@ -342,19 +342,16 @@ typedef bool
                 JS::MutableHandleValue vp);
 typedef bool
 (* PropertyIdOp)(JSContext *cx, JS::HandleObject obj, JS::HandleObject receiver,
                  JS::Handle<PropertyName*> name, JS::MutableHandleValue vp);
 typedef bool
 (* ElementIdOp)(JSContext *cx, JS::HandleObject obj, JS::HandleObject receiver, uint32_t index,
                 JS::MutableHandleValue vp);
 typedef bool
-(* ElementIfPresentOp)(JSContext *cx, JS::HandleObject obj, JS::HandleObject receiver,
-                       uint32_t index, JS::MutableHandleValue vp, bool* present);
-typedef bool
 (* SpecialIdOp)(JSContext *cx, JS::HandleObject obj, JS::HandleObject receiver,
                 HandleSpecialId sid, JS::MutableHandleValue vp);
 typedef bool
 (* StrictGenericIdOp)(JSContext *cx, JS::HandleObject obj, JS::HandleId id,
                       JS::MutableHandleValue vp, bool strict);
 typedef bool
 (* StrictPropertyIdOp)(JSContext *cx, JS::HandleObject obj, JS::Handle<PropertyName*> name,
                        JS::MutableHandleValue vp, bool strict);
@@ -454,17 +451,16 @@ struct ObjectOps
     LookupSpecialOp     lookupSpecial;
     DefineGenericOp     defineGeneric;
     DefinePropOp        defineProperty;
     DefineElementOp     defineElement;
     DefineSpecialOp     defineSpecial;
     GenericIdOp         getGeneric;
     PropertyIdOp        getProperty;
     ElementIdOp         getElement;
-    ElementIfPresentOp  getElementIfPresent; /* can be null */
     SpecialIdOp         getSpecial;
     StrictGenericIdOp   setGeneric;
     StrictPropertyIdOp  setProperty;
     StrictElementIdOp   setElement;
     StrictSpecialIdOp   setSpecial;
     GenericAttributesOp getGenericAttributes;
     GenericAttributesOp setGenericAttributes;
     DeletePropertyOp    deleteProperty;
@@ -475,17 +471,17 @@ struct ObjectOps
 
     JSNewEnumerateOp    enumerate;
     ObjectOp            thisObject;
 };
 
 #define JS_NULL_OBJECT_OPS                                                    \
     {nullptr,nullptr,nullptr,nullptr,nullptr,nullptr,nullptr,nullptr,nullptr, \
      nullptr,nullptr,nullptr,nullptr,nullptr,nullptr,nullptr,nullptr,nullptr, \
-     nullptr,nullptr,nullptr,nullptr,nullptr,nullptr,nullptr,nullptr}
+     nullptr,nullptr,nullptr,nullptr,nullptr,nullptr,nullptr}
 
 } // namespace js
 
 // Classes, objects, and properties.
 
 typedef void (*JSClassInternal)();
 
 struct JSClass {

--- a/js/src/builtin/TypedObject.cpp
+++ b/js/src/builtin/TypedObject.cpp
@@ -2077,63 +2077,51 @@ TypedDatum::obj_getProperty(JSContext *c
     RootedId id(cx, NameToId(name));
     return obj_getGeneric(cx, obj, receiver, id, vp);
 }
 
 bool
 TypedDatum::obj_getElement(JSContext *cx, HandleObject obj, HandleObject receiver,
                              uint32_t index, MutableHandleValue vp)
 {
-    bool present;
-    return obj_getElementIfPresent(cx, obj, receiver, index, vp, &present);
-}
-
-bool
-TypedDatum::obj_getElementIfPresent(JSContext *cx, HandleObject obj,
-                                    HandleObject receiver, uint32_t index,
-                                    MutableHandleValue vp, bool *present)
-{
     RootedObject type(cx, GetType(*obj));
     TypeRepresentation *typeRepr = typeRepresentation(*type);
 
     switch (typeRepr->kind()) {
       case TypeRepresentation::Scalar:
       case TypeRepresentation::Reference:
       case TypeRepresentation::X4:
       case TypeRepresentation::Struct:
         break;
 
       case TypeRepresentation::SizedArray:
       case TypeRepresentation::UnsizedArray:
       {
         JS_ASSERT(IsArrayTypedDatum(*obj));
 
-        *present = true;
-
         if (index >= DatumLength(*obj)) {
             vp.setUndefined();
             return true;
         }
 
         RootedObject elementType(cx, ArrayElementType(*GetType(*obj)));
         SizedTypeRepresentation *elementTypeRepr =
             typeRepresentation(*elementType)->asSized();
         size_t offset = elementTypeRepr->size() * index;
         return Reify(cx, elementTypeRepr, elementType, obj, offset, vp);
       }
     }
 
     RootedObject proto(cx, obj->getProto());
     if (!proto) {
-        *present = false;
         vp.setUndefined();
         return true;
     }
 
-    return JSObject::getElementIfPresent(cx, proto, receiver, index, vp, present);
+    return JSObject::getElement(cx, proto, receiver, index, vp);
 }
 
 bool
 TypedDatum::obj_getSpecial(JSContext *cx, HandleObject obj,
                             HandleObject receiver, HandleSpecialId sid,
                             MutableHandleValue vp)
 {
     RootedId id(cx, SPECIALID_TO_JSID(sid));
@@ -2494,17 +2482,16 @@ const Class TypedObject::class_ = {
         TypedDatum::obj_lookupSpecial,
         TypedDatum::obj_defineGeneric,
         TypedDatum::obj_defineProperty,
         TypedDatum::obj_defineElement,
         TypedDatum::obj_defineSpecial,
         TypedDatum::obj_getGeneric,
         TypedDatum::obj_getProperty,
         TypedDatum::obj_getElement,
-        TypedDatum::obj_getElementIfPresent,
         TypedDatum::obj_getSpecial,
         TypedDatum::obj_setGeneric,
         TypedDatum::obj_setProperty,
         TypedDatum::obj_setElement,
         TypedDatum::obj_setSpecial,
         TypedDatum::obj_getGenericAttributes,
         TypedDatum::obj_setGenericAttributes,
         TypedDatum::obj_deleteProperty,
@@ -2661,17 +2648,16 @@ const Class TypedHandle::class_ = {
         TypedDatum::obj_lookupSpecial,
         TypedDatum::obj_defineGeneric,
         TypedDatum::obj_defineProperty,
         TypedDatum::obj_defineElement,
         TypedDatum::obj_defineSpecial,
         TypedDatum::obj_getGeneric,
         TypedDatum::obj_getProperty,
         TypedDatum::obj_getElement,
-        TypedDatum::obj_getElementIfPresent,
         TypedDatum::obj_getSpecial,
         TypedDatum::obj_setGeneric,
         TypedDatum::obj_setProperty,
         TypedDatum::obj_setElement,
         TypedDatum::obj_setSpecial,
         TypedDatum::obj_getGenericAttributes,
         TypedDatum::obj_setGenericAttributes,
         TypedDatum::obj_deleteProperty,

--- a/js/src/builtin/TypedObject.h
+++ b/js/src/builtin/TypedObject.h
@@ -288,19 +288,16 @@ class TypedDatum : public JSObject
                                 HandlePropertyName name, MutableHandleValue vp);
 
     static bool obj_getElement(JSContext *cx, HandleObject obj, HandleObject receiver,
                                uint32_t index, MutableHandleValue vp);
 
     static bool obj_getSpecial(JSContext *cx, HandleObject obj, HandleObject receiver,
                                HandleSpecialId sid, MutableHandleValue vp);
 
-    static bool obj_getElementIfPresent(JSContext *cx, HandleObject obj,
-                                        HandleObject receiver, uint32_t index,
-                                        MutableHandleValue vp, bool *present);
     static bool obj_setGeneric(JSContext *cx, HandleObject obj, HandleId id,
                                MutableHandleValue vp, bool strict);
     static bool obj_setProperty(JSContext *cx, HandleObject obj, HandlePropertyName name,
                                 MutableHandleValue vp, bool strict);
     static bool obj_setElement(JSContext *cx, HandleObject obj, uint32_t index,
                                MutableHandleValue vp, bool strict);
     static bool obj_setSpecial(JSContext *cx, HandleObject obj,
                                HandleSpecialId sid, MutableHandleValue vp, bool strict);

--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -3389,35 +3389,16 @@ JS_ForwardGetElementTo(JSContext *cx, JS
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj);
     JSAutoResolveFlags rf(cx, 0);
 
     return JSObject::getElement(cx, obj, onBehalfOf, index, vp);
 }
 
 JS_PUBLIC_API(bool)
-JS_GetElementIfPresent(JSContext *cx, JSObject *objArg, uint32_t index, JSObject *onBehalfOfArg,
-                       MutableHandleValue vp, bool* present)
-{
-    RootedObject obj(cx, objArg);
-    RootedObject onBehalfOf(cx, onBehalfOfArg);
-    AssertHeapIsIdle(cx);
-    CHECK_REQUEST(cx);
-    assertSameCompartment(cx, obj);
-    JSAutoResolveFlags rf(cx, 0);
-
-    bool isPresent;
-    if (!JSObject::getElementIfPresent(cx, obj, onBehalfOf, index, vp, &isPresent))
-        return false;
-
-    *present = isPresent;
-    return true;
-}
-
-JS_PUBLIC_API(bool)
 JS_GetProperty(JSContext *cx, JSObject *objArg, const char *name, MutableHandleValue vp)
 {
     RootedObject obj(cx, objArg);
     JSAtom *atom = Atomize(cx, name, strlen(name));
     return atom && JS_GetPropertyById(cx, obj, AtomToId(atom), vp);
 }
 
 JS_PUBLIC_API(bool)

--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -3035,25 +3035,16 @@ JS_LookupElement(JSContext *cx, JSObject
 
 extern JS_PUBLIC_API(bool)
 JS_GetElement(JSContext *cx, JSObject *obj, uint32_t index, JS::MutableHandle<JS::Value> vp);
 
 extern JS_PUBLIC_API(bool)
 JS_ForwardGetElementTo(JSContext *cx, JSObject *obj, uint32_t index, JSObject *onBehalfOf,
                        JS::MutableHandle<JS::Value> vp);
 
-/*
- * Get the property with name given by |index|, if it has one.  If
- * not, |*present| will be set to false and the value of |vp| must not
- * be relied on.
- */
-extern JS_PUBLIC_API(bool)
-JS_GetElementIfPresent(JSContext *cx, JSObject *obj, uint32_t index, JSObject *onBehalfOf,
-                       JS::MutableHandle<JS::Value> vp, bool* present);
-
 extern JS_PUBLIC_API(bool)
 JS_SetElement(JSContext *cx, JSObject *obj, uint32_t index, JS::MutableHandle<JS::Value> vp);
 
 extern JS_PUBLIC_API(bool)
 JS_DeleteElement(JSContext *cx, JSObject *obj, uint32_t index);
 
 extern JS_PUBLIC_API(bool)
 JS_DeleteElement2(JSContext *cx, JSObject *obj, uint32_t index, bool *succeeded);

--- a/js/src/jsarray.cpp
+++ b/js/src/jsarray.cpp
@@ -129,37 +129,44 @@ js::StringIsArrayIndex(JSLinearString *s
         *indexp = index;
         return true;
     }
 
     return false;
 }
 
 static bool
-DoubleIndexToId(JSContext *cx, double index, MutableHandleId id)
+ToId(JSContext *cx, double index, MutableHandleId id)
 {
     if (index == uint32_t(index))
         return IndexToId(cx, uint32_t(index), id.address());
 
     Value tmp = DoubleValue(index);
     return ValueToId<CanGC>(cx, HandleValue::fromMarkedLocation(&tmp), id);
 }
 
+static bool
+ToId(JSContext *cx, uint32_t index, MutableHandleId id)
+{
+    return IndexToId(cx, index, id.address());
+}
+
 /*
  * If the property at the given index exists, get its value into location
  * pointed by vp and set *hole to false. Otherwise set *hole to true and *vp
  * to JSVAL_VOID. This function assumes that the location pointed by vp is
  * properly rooted and can be used as GC-protected storage for temporaries.
  */
+template<typename IndexType>
 static inline bool
-DoGetElement(JSContext *cx, HandleObject obj, double index, bool *hole, MutableHandleValue vp)
+DoGetElement(JSContext *cx, HandleObject obj, IndexType index, bool *hole, MutableHandleValue vp)
 {
     RootedId id(cx);
 
-    if (!DoubleIndexToId(cx, index, &id))
+    if (!ToId(cx, index, &id))
         return false;
 
     RootedObject obj2(cx);
     RootedShape prop(cx);
     if (!JSObject::lookupGeneric(cx, obj, id, &obj2, &prop))
         return false;
 
     if (!prop) {
@@ -168,30 +175,16 @@ DoGetElement(JSContext *cx, HandleObject
     } else {
         if (!JSObject::getGeneric(cx, obj, obj, id, vp))
             return false;
         *hole = false;
     }
     return true;
 }
 
-static inline bool
-DoGetElement(JSContext *cx, HandleObject obj, uint32_t index, bool *hole, MutableHandleValue vp)
-{
-    bool present;
-    if (!JSObject::getElementIfPresent(cx, obj, obj, index, vp, &present))
-        return false;
-
-    *hole = !present;
-    if (*hole)
-        vp.setUndefined();
-
-    return true;
-}
-
 template<typename IndexType>
 static void
 AssertGreaterThanZero(IndexType index)
 {
     JS_ASSERT(index >= 0);
     JS_ASSERT(index == floor(index));
 }
 
@@ -291,17 +284,17 @@ SetArrayElement(JSContext *cx, HandleObj
         } while (false);
 
         if (result == JSObject::ED_FAILED)
             return false;
         JS_ASSERT(result == JSObject::ED_SPARSE);
     }
 
     RootedId id(cx);
-    if (!DoubleIndexToId(cx, index, &id))
+    if (!ToId(cx, index, &id))
         return false;
 
     RootedValue tmp(cx, v);
     return JSObject::setGeneric(cx, obj, obj, id, &tmp, true);
 }
 
 /*
  * Attempt to delete the element |index| from |obj| as if by

--- a/js/src/jsobj.h
+++ b/js/src/jsobj.h
@@ -1025,22 +1025,16 @@ class JSObject : public js::ObjectImpl
         return getGenericNoGC(cx, obj, receiver, js::NameToId(name), vp);
     }
 
     static inline bool getElement(JSContext *cx, js::HandleObject obj, js::HandleObject receiver,
                                   uint32_t index, js::MutableHandleValue vp);
     static inline bool getElementNoGC(JSContext *cx, JSObject *obj, JSObject *receiver,
                                       uint32_t index, js::Value *vp);
 
-    /* If element is not present (e.g. array hole) *present is set to
-       false and the contents of *vp are unusable garbage. */
-    static inline bool getElementIfPresent(JSContext *cx, js::HandleObject obj,
-                                           js::HandleObject receiver, uint32_t index,
-                                           js::MutableHandleValue vp, bool *present);
-
     static bool getSpecial(JSContext *cx, js::HandleObject obj,
                            js::HandleObject receiver, js::SpecialId sid,
                            js::MutableHandleValue vp)
     {
         JS::RootedId id(cx, SPECIALID_TO_JSID(sid));
         return getGeneric(cx, obj, receiver, id, vp);
     }
 

--- a/js/src/jsobjinlines.h
+++ b/js/src/jsobjinlines.h
@@ -578,48 +578,16 @@ JSObject::getElementNoGC(JSContext *cx, 
         return false;
 
     jsid id;
     if (!js::IndexToId(cx, index, &id))
         return false;
     return getGenericNoGC(cx, obj, receiver, id, vp);
 }
 
-/* static */ inline bool
-JSObject::getElementIfPresent(JSContext *cx, js::HandleObject obj, js::HandleObject receiver,
-                              uint32_t index, js::MutableHandleValue vp,
-                              bool *present)
-{
-    js::ElementIfPresentOp op = obj->getOps()->getElementIfPresent;
-    if (op)
-        return op(cx, obj, receiver, index, vp, present);
-
-    /*
-     * For now, do the index-to-id conversion just once, then use
-     * lookupGeneric/getGeneric.  Once lookupElement and getElement stop both
-     * doing index-to-id conversions, we can use those here.
-     */
-    JS::RootedId id(cx);
-    if (!js::IndexToId(cx, index, id.address()))
-        return false;
-
-    JS::RootedObject obj2(cx);
-    js::RootedShape prop(cx);
-    if (!lookupGeneric(cx, obj, id, &obj2, &prop))
-        return false;
-
-    if (!prop) {
-        *present = false;
-        return true;
-    }
-
-    *present = true;
-    return getGeneric(cx, obj, receiver, id, vp);
-}
-
 inline js::GlobalObject &
 JSObject::global() const
 {
 #ifdef DEBUG
     JSObject *obj = const_cast<JSObject *>(this);
     while (JSObject *parent = obj->getParent())
         obj = parent;
 #endif

--- a/js/src/jsproxy.cpp
+++ b/js/src/jsproxy.cpp
@@ -147,37 +147,16 @@ BaseProxyHandler::get(JSContext *cx, Han
     if (desc.hasShortId()) {
         RootedId id(cx, INT_TO_JSID(desc.shortid()));
         return CallJSPropertyOp(cx, desc.getter(), receiver, id, vp);
     }
     return CallJSPropertyOp(cx, desc.getter(), receiver, id, vp);
 }
 
 bool
-BaseProxyHandler::getElementIfPresent(JSContext *cx, HandleObject proxy, HandleObject receiver,
-                                      uint32_t index, MutableHandleValue vp, bool *present)
-{
-    RootedId id(cx);
-    if (!IndexToId(cx, index, id.address()))
-        return false;
-
-    assertEnteredPolicy(cx, proxy, id);
-
-    if (!has(cx, proxy, id, present))
-        return false;
-
-    if (!*present) {
-        Debug_SetValueRangeToCrashOnTouch(vp.address(), 1);
-        return true;
-    }
-
-    return get(cx, proxy, receiver, id, vp);
-}
-
-bool
 BaseProxyHandler::set(JSContext *cx, HandleObject proxy, HandleObject receiver,
                       HandleId id, bool strict, MutableHandleValue vp)
 {
     assertEnteredPolicy(cx, proxy, id);
 
     Rooted<PropertyDescriptor> desc(cx);
     if (!getOwnPropertyDescriptor(cx, proxy, id, &desc, JSRESOLVE_ASSIGNING))
         return false;
@@ -2514,51 +2493,16 @@ Proxy::callProp(JSContext *cx, HandleObj
         if (!OnUnknownMethod(cx, proxy, IdToValue(id), vp))
             return false;
     }
 #endif
 
     return true;
 }
 
-
-bool
-Proxy::getElementIfPresent(JSContext *cx, HandleObject proxy, HandleObject receiver, uint32_t index,
-                           MutableHandleValue vp, bool *present)
-{
-    JS_CHECK_RECURSION(cx, return false);
-
-    RootedId id(cx);
-    if (!IndexToId(cx, index, id.address()))
-        return false;
-
-    BaseProxyHandler *handler = proxy->as<ProxyObject>().handler();
-    AutoEnterPolicy policy(cx, handler, proxy, id, BaseProxyHandler::GET, true);
-    if (!policy.allowed())
-        return policy.returnValue();
-
-    if (!handler->hasPrototype()) {
-        return handler->getElementIfPresent(cx, proxy, receiver, index,
-                                            vp, present);
-    }
-
-    bool hasOwn;
-    if (!handler->hasOwn(cx, proxy, id, &hasOwn))
-        return false;
-
-    if (hasOwn) {
-        *present = true;
-        return proxy->as<ProxyObject>().handler()->get(cx, proxy, receiver, id, vp);
-    }
-
-    *present = false;
-    INVOKE_ON_PROTOTYPE(cx, handler, proxy,
-                        JSObject::getElementIfPresent(cx, proto, receiver, index, vp, present));
-}
-
 bool
 Proxy::set(JSContext *cx, HandleObject proxy, HandleObject receiver, HandleId id, bool strict,
            MutableHandleValue vp)
 {
     JS_CHECK_RECURSION(cx, return false);
     BaseProxyHandler *handler = proxy->as<ProxyObject>().handler();
     AutoEnterPolicy policy(cx, handler, proxy, id, BaseProxyHandler::SET, true);
     if (!policy.allowed())
@@ -2887,23 +2831,16 @@ proxy_GetElement(JSContext *cx, HandleOb
 {
     RootedId id(cx);
     if (!IndexToId(cx, index, id.address()))
         return false;
     return proxy_GetGeneric(cx, obj, receiver, id, vp);
 }
 
 static bool
-proxy_GetElementIfPresent(JSContext *cx, HandleObject obj, HandleObject receiver, uint32_t index,
-                          MutableHandleValue vp, bool *present)
-{
-    return Proxy::getElementIfPresent(cx, obj, receiver, index, vp, present);
-}
-
-static bool
 proxy_GetSpecial(JSContext *cx, HandleObject obj, HandleObject receiver, HandleSpecialId sid,
                  MutableHandleValue vp)
 {
     Rooted<jsid> id(cx, SPECIALID_TO_JSID(sid));
     return proxy_GetGeneric(cx, obj, receiver, id, vp);
 }
 
 static bool
@@ -3123,17 +3060,16 @@ proxy_Unwatch(JSContext *cx, JS::HandleO
         proxy_LookupSpecial,                        \
         proxy_DefineGeneric,                        \
         proxy_DefineProperty,                       \
         proxy_DefineElement,                        \
         proxy_DefineSpecial,                        \
         proxy_GetGeneric,                           \
         proxy_GetProperty,                          \
         proxy_GetElement,                           \
-        proxy_GetElementIfPresent,                  \
         proxy_GetSpecial,                           \
         proxy_SetGeneric,                           \
         proxy_SetProperty,                          \
         proxy_SetElement,                           \
         proxy_SetSpecial,                           \
         proxy_GetGenericAttributes,                 \
         proxy_SetGenericAttributes,                 \
         proxy_DeleteProperty,                       \
@@ -3181,17 +3117,16 @@ const Class js::OuterWindowProxyObject::
         proxy_LookupSpecial,
         proxy_DefineGeneric,
         proxy_DefineProperty,
         proxy_DefineElement,
         proxy_DefineSpecial,
         proxy_GetGeneric,
         proxy_GetProperty,
         proxy_GetElement,
-        proxy_GetElementIfPresent,
         proxy_GetSpecial,
         proxy_SetGeneric,
         proxy_SetProperty,
         proxy_SetElement,
         proxy_SetSpecial,
         proxy_GetGenericAttributes,
         proxy_SetGenericAttributes,
         proxy_DeleteProperty,

--- a/js/src/jsproxy.h
+++ b/js/src/jsproxy.h
@@ -161,18 +161,16 @@ class JS_FRIEND_API(BaseProxyHandler)
     virtual bool nativeCall(JSContext *cx, IsAcceptableThis test, NativeImpl impl, CallArgs args);
     virtual bool hasInstance(JSContext *cx, HandleObject proxy, MutableHandleValue v, bool *bp);
     virtual bool objectClassIs(HandleObject obj, ESClassValue classValue, JSContext *cx);
     virtual const char *className(JSContext *cx, HandleObject proxy);
     virtual JSString *fun_toString(JSContext *cx, HandleObject proxy, unsigned indent);
     virtual bool regexp_toShared(JSContext *cx, HandleObject proxy, RegExpGuard *g);
     virtual bool defaultValue(JSContext *cx, HandleObject obj, JSType hint, MutableHandleValue vp);
     virtual void finalize(JSFreeOp *fop, JSObject *proxy);
-    virtual bool getElementIfPresent(JSContext *cx, HandleObject obj, HandleObject receiver,
-                                     uint32_t index, MutableHandleValue vp, bool *present);
     virtual bool getPrototypeOf(JSContext *cx, HandleObject proxy, MutableHandleObject protop);
 
     // These two hooks must be overridden, or not overridden, in tandem -- no
     // overriding just one!
     virtual bool watch(JSContext *cx, JS::HandleObject proxy, JS::HandleId id,
                        JS::HandleObject callable);
     virtual bool unwatch(JSContext *cx, JS::HandleObject proxy, JS::HandleId id);
 
@@ -271,18 +269,16 @@ class Proxy
     static bool delete_(JSContext *cx, HandleObject proxy, HandleId id, bool *bp);
     static bool enumerate(JSContext *cx, HandleObject proxy, AutoIdVector &props);
 
     /* ES5 Harmony derived proxy traps. */
     static bool has(JSContext *cx, HandleObject proxy, HandleId id, bool *bp);
     static bool hasOwn(JSContext *cx, HandleObject proxy, HandleId id, bool *bp);
     static bool get(JSContext *cx, HandleObject proxy, HandleObject receiver, HandleId id,
                     MutableHandleValue vp);
-    static bool getElementIfPresent(JSContext *cx, HandleObject proxy, HandleObject receiver,
-                                    uint32_t index, MutableHandleValue vp, bool *present);
     static bool set(JSContext *cx, HandleObject proxy, HandleObject receiver, HandleId id,
                     bool strict, MutableHandleValue vp);
     static bool keys(JSContext *cx, HandleObject proxy, AutoIdVector &props);
     static bool iterate(JSContext *cx, HandleObject proxy, unsigned flags, MutableHandleValue vp);
 
     /* Spidermonkey extensions. */
     static bool isExtensible(JSContext *cx, HandleObject proxy, bool *extensible);
     static bool call(JSContext *cx, HandleObject proxy, const CallArgs &args);

--- a/js/src/jswrapper.cpp
+++ b/js/src/jswrapper.cpp
@@ -833,24 +833,16 @@ DeadObjectProxy::regexp_toShared(JSConte
 bool
 DeadObjectProxy::defaultValue(JSContext *cx, HandleObject obj, JSType hint, MutableHandleValue vp)
 {
     JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_DEAD_OBJECT);
     return false;
 }
 
 bool
-DeadObjectProxy::getElementIfPresent(JSContext *cx, HandleObject obj, HandleObject receiver,
-                                     uint32_t index, MutableHandleValue vp, bool *present)
-{
-    JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_DEAD_OBJECT);
-    return false;
-}
-
-bool
 DeadObjectProxy::getPrototypeOf(JSContext *cx, HandleObject proxy, MutableHandleObject protop)
 {
     protop.set(nullptr);
     return true;
 }
 
 DeadObjectProxy DeadObjectProxy::singleton;
 const char DeadObjectProxy::sDeadObjectFamily = 0;

--- a/js/src/jswrapper.h
+++ b/js/src/jswrapper.h
@@ -203,19 +203,16 @@ class JS_FRIEND_API(DeadObjectProxy) : p
                              bool *bp) MOZ_OVERRIDE;
     virtual bool objectClassIs(HandleObject obj, ESClassValue classValue,
                                JSContext *cx) MOZ_OVERRIDE;
     virtual const char *className(JSContext *cx, HandleObject proxy) MOZ_OVERRIDE;
     virtual JSString *fun_toString(JSContext *cx, HandleObject proxy, unsigned indent) MOZ_OVERRIDE;
     virtual bool regexp_toShared(JSContext *cx, HandleObject proxy, RegExpGuard *g) MOZ_OVERRIDE;
     virtual bool defaultValue(JSContext *cx, HandleObject obj, JSType hint,
                               MutableHandleValue vp) MOZ_OVERRIDE;
-    virtual bool getElementIfPresent(JSContext *cx, HandleObject obj, HandleObject receiver,
-                                     uint32_t index, MutableHandleValue vp,
-                                     bool *present) MOZ_OVERRIDE;
     virtual bool getPrototypeOf(JSContext *cx, HandleObject proxy,
                                 MutableHandleObject protop) MOZ_OVERRIDE;
 
     static DeadObjectProxy singleton;
 };
 
 extern JSObject *
 TransparentObjectWrapper(JSContext *cx, HandleObject existing, HandleObject obj,

--- a/js/src/vm/ScopeObject.cpp
+++ b/js/src/vm/ScopeObject.cpp
@@ -551,17 +551,16 @@ const Class WithObject::class_ = {
         with_LookupSpecial,
         nullptr,             /* defineGeneric */
         nullptr,             /* defineProperty */
         nullptr,             /* defineElement */
         nullptr,             /* defineSpecial */
         with_GetGeneric,
         with_GetProperty,
         with_GetElement,
-        nullptr,             /* getElementIfPresent */
         with_GetSpecial,
         with_SetGeneric,
         with_SetProperty,
         with_SetElement,
         with_SetSpecial,
         with_GetGenericAttributes,
         with_SetGenericAttributes,
         with_DeleteProperty,

--- a/js/src/vm/TypedArrayObject.cpp
+++ b/js/src/vm/TypedArrayObject.cpp
@@ -1033,26 +1033,16 @@ ArrayBufferObject::obj_getElement(JSCont
 {
     RootedObject delegate(cx, ArrayBufferDelegate(cx, obj));
     if (!delegate)
         return false;
     return baseops::GetElement(cx, delegate, receiver, index, vp);
 }
 
 bool
-ArrayBufferObject::obj_getElementIfPresent(JSContext *cx, HandleObject obj, HandleObject receiver,
-                                           uint32_t index, MutableHandleValue vp, bool *present)
-{
-    RootedObject delegate(cx, ArrayBufferDelegate(cx, obj));
-    if (!delegate)
-        return false;
-    return JSObject::getElementIfPresent(cx, delegate, receiver, index, vp, present);
-}
-
-bool
 ArrayBufferObject::obj_getSpecial(JSContext *cx, HandleObject obj,
                                   HandleObject receiver, HandleSpecialId sid,
                                   MutableHandleValue vp)
 {
     Rooted<jsid> id(cx, SPECIALID_TO_JSID(sid));
     return obj_getGeneric(cx, obj, receiver, id, vp);
 }
 
@@ -1490,37 +1480,16 @@ class TypedArrayObjectTemplate : public 
         if (atom->isIndex(&index))
             return obj_getElement(cx, obj, receiver, index, vp);
 
         Rooted<PropertyName*> name(cx, atom->asPropertyName());
         return obj_getProperty(cx, obj, receiver, name, vp);
     }
 
     static bool
-    obj_getElementIfPresent(JSContext *cx, HandleObject tarray, HandleObject receiver, uint32_t index,
-                            MutableHandleValue vp, bool *present)
-    {
-        // Fast-path the common case of index < length
-        if (index < tarray->as<TypedArrayObject>().length()) {
-            // this inline function is specialized for each type
-            copyIndexToValue(tarray, index, vp);
-            *present = true;
-            return true;
-        }
-
-        RootedObject proto(cx, tarray->getProto());
-        if (!proto) {
-            vp.setUndefined();
-            return true;
-        }
-
-        return JSObject::getElementIfPresent(cx, proto, receiver, index, vp, present);
-    }
-
-    static bool
     setElementTail(JSContext *cx, HandleObject tarray, uint32_t index,
                    MutableHandleValue vp, bool strict)
     {
         JS_ASSERT(tarray);
         JS_ASSERT(index < tarray->as<TypedArrayObject>().length());
 
         if (vp.isInt32()) {
             setIndex(tarray, index, NativeType(vp.toInt32()));
@@ -3475,17 +3444,16 @@ const Class ArrayBufferObject::class_ = 
         ArrayBufferObject::obj_lookupSpecial,
         ArrayBufferObject::obj_defineGeneric,
         ArrayBufferObject::obj_defineProperty,
         ArrayBufferObject::obj_defineElement,
         ArrayBufferObject::obj_defineSpecial,
         ArrayBufferObject::obj_getGeneric,
         ArrayBufferObject::obj_getProperty,
         ArrayBufferObject::obj_getElement,
-        ArrayBufferObject::obj_getElementIfPresent,
         ArrayBufferObject::obj_getSpecial,
         ArrayBufferObject::obj_setGeneric,
         ArrayBufferObject::obj_setProperty,
         ArrayBufferObject::obj_setElement,
         ArrayBufferObject::obj_setSpecial,
         ArrayBufferObject::obj_getGenericAttributes,
         ArrayBufferObject::obj_setGenericAttributes,
         ArrayBufferObject::obj_deleteProperty,
@@ -3638,17 +3606,16 @@ IMPL_TYPED_ARRAY_COMBINED_UNWRAPPERS(Flo
         _typedArray##Object::obj_lookupSpecial,                                \
         _typedArray##Object::obj_defineGeneric,                                \
         _typedArray##Object::obj_defineProperty,                               \
         _typedArray##Object::obj_defineElement,                                \
         _typedArray##Object::obj_defineSpecial,                                \
         _typedArray##Object::obj_getGeneric,                                   \
         _typedArray##Object::obj_getProperty,                                  \
         _typedArray##Object::obj_getElement,                                   \
-        _typedArray##Object::obj_getElementIfPresent,                          \
         _typedArray##Object::obj_getSpecial,                                   \
         _typedArray##Object::obj_setGeneric,                                   \
         _typedArray##Object::obj_setProperty,                                  \
         _typedArray##Object::obj_setElement,                                   \
         _typedArray##Object::obj_setSpecial,                                   \
         _typedArray##Object::obj_getGenericAttributes,                         \
         _typedArray##Object::obj_setGenericAttributes,                         \
         _typedArray##Object::obj_deleteProperty,                               \

--- a/js/src/vm/TypedArrayObject.h
+++ b/js/src/vm/TypedArrayObject.h
@@ -102,18 +102,16 @@ class ArrayBufferObject : public JSObjec
     static bool obj_getGeneric(JSContext *cx, HandleObject obj, HandleObject receiver,
                                HandleId id, MutableHandleValue vp);
 
     static bool obj_getProperty(JSContext *cx, HandleObject obj, HandleObject receiver,
                                 HandlePropertyName name, MutableHandleValue vp);
 
     static bool obj_getElement(JSContext *cx, HandleObject obj, HandleObject receiver,
                                uint32_t index, MutableHandleValue vp);
-    static bool obj_getElementIfPresent(JSContext *cx, HandleObject obj, HandleObject receiver,
-                                        uint32_t index, MutableHandleValue vp, bool *present);
 
     static bool obj_getSpecial(JSContext *cx, HandleObject obj, HandleObject receiver,
                                HandleSpecialId sid, MutableHandleValue vp);
 
     static bool obj_setGeneric(JSContext *cx, HandleObject obj, HandleId id,
                                MutableHandleValue vp, bool strict);
     static bool obj_setProperty(JSContext *cx, HandleObject obj, HandlePropertyName name,
                                 MutableHandleValue vp, bool strict);

--- a/js/xpconnect/src/XPCWrappedNativeJSOps.cpp
+++ b/js/xpconnect/src/XPCWrappedNativeJSOps.cpp
@@ -715,17 +715,16 @@ const XPCWrappedNativeJSClass XPC_WN_NoH
         nullptr, // lookupSpecial
         nullptr, // defineGeneric
         nullptr, // defineProperty
         nullptr, // defineElement
         nullptr, // defineSpecial
         nullptr, // getGeneric
         nullptr, // getProperty
         nullptr, // getElement
-        nullptr, // getElementIfPresent
         nullptr, // getSpecial
         nullptr, // setGeneric
         nullptr, // setProperty
         nullptr, // setElement
         nullptr, // setSpecial
         nullptr, // getGenericAttributes
         nullptr, // setGenericAttributes
         nullptr, // deleteProperty

--- a/js/xpconnect/src/xpcprivate.h
+++ b/js/xpconnect/src/xpcprivate.h
@@ -976,17 +976,16 @@ XPC_WN_JSOp_ThisObject(JSContext *cx, JS
         nullptr, /* lookupSpecial */                                          \
         nullptr, /* defineGeneric */                                          \
         nullptr, /* defineProperty */                                         \
         nullptr, /* defineElement */                                          \
         nullptr, /* defineSpecial */                                          \
         nullptr, /* getGeneric    */                                          \
         nullptr, /* getProperty    */                                         \
         nullptr, /* getElement    */                                          \
-        nullptr, /* getElementIfPresent */                                    \
         nullptr, /* getSpecial    */                                          \
         nullptr, /* setGeneric    */                                          \
         nullptr, /* setProperty    */                                         \
         nullptr, /* setElement    */                                          \
         nullptr, /* setSpecial    */                                          \
         nullptr, /* getGenericAttributes  */                                  \
         nullptr, /* setGenericAttributes  */                                  \
         nullptr, /* deleteProperty */                                         \
@@ -1005,17 +1004,16 @@ XPC_WN_JSOp_ThisObject(JSContext *cx, JS
         nullptr, /* lookupSpecial */                                          \
         nullptr, /* defineGeneric */                                          \
         nullptr, /* defineProperty */                                         \
         nullptr, /* defineElement */                                          \
         nullptr, /* defineSpecial */                                          \
         nullptr, /* getGeneric    */                                          \
         nullptr, /* getProperty    */                                         \
         nullptr, /* getElement    */                                          \
-        nullptr, /* getElementIfPresent */                                    \
         nullptr, /* getSpecial    */                                          \
         nullptr, /* setGeneric    */                                          \
         nullptr, /* setProperty    */                                         \
         nullptr, /* setElement    */                                          \
         nullptr, /* setSpecial    */                                          \
         nullptr, /* getGenericAttributes  */                                  \
         nullptr, /* setGenericAttributes  */                                  \
         nullptr, /* deleteProperty */                                         \