Use GetProperty for getting elements.

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 6365 matching lines @@
 
 
 size_t v8::ArrayBufferView::ByteLength() {
   i::Handle<i::JSArrayBufferView> obj = Utils::OpenHandle(this);
   return static_cast<size_t>(obj->byte_length()->Number());
 }
 
 
 size_t v8::TypedArray::Length() {
   i::Handle<i::JSTypedArray> obj = Utils::OpenHandle(this);
-  return static_cast<size_t>(obj->length()->Number());
+  return static_cast<size_t>(obj->length_value());
 }
 
 
 #define TYPED_ARRAY_NEW(Type, type, TYPE, ctype, size)                       \
   Local<Type##Array> Type##Array::New(Handle<ArrayBuffer> array_buffer,      \
                                       size_t byte_offset, size_t length) {   \
     i::Isolate* isolate = Utils::OpenHandle(*array_buffer)->GetIsolate();    \
     LOG_API(isolate,                                                         \
             "v8::" #Type "Array::New(Handle<ArrayBuffer>, size_t, size_t)"); \
     ENTER_V8(isolate);                                                       \
@@ skipping 1682 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal