Turn WorkerLoaderProxy into a threadsafe, ref-counted object.

Source/core/workers/WorkerLoaderProxy.cpp

+// Copyright 2015 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 "config.h"
+
+#include "core/workers/WorkerLoaderProxy.h"
+
+#include "core/dom/ExecutionContextTask.h"
+
+namespace blink {
+
+WorkerLoaderProxy::WorkerLoaderProxy(WorkerLoaderProxyProvider* loaderProxyProvider)
+    : m_loaderProxyProvider(loaderProxyProvider)
+{
+}
+
+WorkerLoaderProxy::~WorkerLoaderProxy()
+{
+    ASSERT(!m_loaderProxyProvider);
+}
+
+void WorkerLoaderProxy::detachProvider(WorkerLoaderProxyProvider* proxyProvider)
+{
+    MutexLocker locker(m_lock);
+    ASSERT_UNUSED(proxyProvider, proxyProvider == m_loaderProxyProvider);
+    m_loaderProxyProvider = nullptr;
+}
+
+void WorkerLoaderProxy::postTaskToLoader(PassOwnPtr<ExecutionContextTask> task)
+{
+    MutexLocker locker(m_lock);
+    if (!m_loaderProxyProvider)
+        return;
+
+    m_loaderProxyProvider->postTaskToLoader(task);
+}
+
+bool WorkerLoaderProxy::postTaskToWorkerGlobalScope(PassOwnPtr<ExecutionContextTask> task)
+{
+    MutexLocker locker(m_lock);
+    if (!m_loaderProxyProvider)
+        return false;
+
+    return m_loaderProxyProvider->postTaskToWorkerGlobalScope(task);
+}
+
+} // namespace blink