Begin implementing V8 bindings for Mojo

mojo/apps/js/v8_environment.cc

 // Copyright 2013 The Chromium 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 "mojo/apps/js/v8_environment.h"
 
 #include <stdlib.h>
 #include <string.h>
 
+#include "mojo/public/bindings/js/v8_array_buffer.h"
 #include "mojo/public/system/macros.h"
 #include "v8/include/v8.h"
 
 namespace mojo {
 namespace apps {
 
 namespace {
 
-class ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
-  virtual void* Allocate(size_t length) MOJO_OVERRIDE {
-    return calloc(1, length);
-  }
-  virtual void* AllocateUninitialized(size_t length) MOJO_OVERRIDE {
-    return malloc(length);
-  }
-  virtual void Free(void* data, size_t length) MOJO_OVERRIDE {
-    free(data);
-  }
-};
-
 bool GenerateEntropy(unsigned char* buffer, size_t amount) {
   // TODO(abarth): Mojo needs a source of entropy.
   // https://code.google.com/p/chromium/issues/detail?id=316387
   return false;
 }
 
 const char kFlags[] = "--use_strict --harmony";
 
 }
 
 void InitializeV8() {
-  v8::V8::SetArrayBufferAllocator(new ArrayBufferAllocator());
+  v8::V8::SetArrayBufferAllocator(js::ArrayBufferAllocator::SharedInstance());
   v8::V8::InitializeICU();
   v8::V8::SetFlagsFromString(kFlags, strlen(kFlags));
   v8::V8::SetEntropySource(&GenerateEntropy);
   v8::V8::Initialize();
 }
 
 }  // namespace apps
 }  // mojo