Moves around mojo js bindings code

mojo/apps/js/bindings/waiting_callback.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/bindings/waiting_callback.h"
-
-#include "gin/per_context_data.h"
-
-namespace mojo {
-namespace js {
-
-namespace {
-
-v8::Handle<v8::String> GetHiddenPropertyName(v8::Isolate* isolate) {
-  return gin::StringToSymbol(isolate, "::mojo::js::WaitingCallback");
-}
-
-}  // namespace
-
-gin::WrapperInfo WaitingCallback::kWrapperInfo = { gin::kEmbedderNativeGin };
-
-WaitingCallback::WaitingCallback(v8::Isolate* isolate,
-                                 v8::Handle<v8::Function> callback)
-      : wait_id_() {
-  v8::Handle<v8::Context> context = isolate->GetCurrentContext();
-  runner_ = gin::PerContextData::From(context)->runner()->GetWeakPtr();
-  GetWrapper(isolate)->SetHiddenValue(GetHiddenPropertyName(isolate), callback);
-}
-
-WaitingCallback::~WaitingCallback() {
-  DCHECK(!wait_id_) << "Waiting callback was destroyed before being cancelled.";
-}
-
-gin::Handle<WaitingCallback> WaitingCallback::Create(
-    v8::Isolate* isolate, v8::Handle<v8::Function> callback) {
-  return gin::CreateHandle(isolate, new WaitingCallback(isolate, callback));
-}
-
-// static
-void WaitingCallback::CallOnHandleReady(void* closure, MojoResult result) {
-  static_cast<WaitingCallback*>(closure)->OnHandleReady(result);
-}
-
-void WaitingCallback::OnHandleReady(MojoResult result) {
-  wait_id_ = 0;
-
-  if (!runner_)
-    return;
-
-  gin::Runner::Scope scope(runner_.get());
-  v8::Isolate* isolate = runner_->GetContextHolder()->isolate();
-
-  v8::Handle<v8::Value> hidden_value =
-      GetWrapper(isolate)->GetHiddenValue(GetHiddenPropertyName(isolate));
-  v8::Handle<v8::Function> callback;
-  CHECK(gin::ConvertFromV8(isolate, hidden_value, &callback));
-
-  v8::Handle<v8::Value> args[] = { gin::ConvertToV8(isolate, result) };
-  runner_->Call(callback, runner_->global(), 1, args);
-}
-
-}  // namespace js
-}  // namespace mojo