Turn WorkerLoaderProxy into a threadsafe, ref-counted object.

Source/core/workers/WorkerMessagingProxy.h

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 28 matching lines @@
 
 namespace blink {
 
 class WorkerObjectProxy;
 class DedicatedWorkerThread;
 class ExecutionContext;
 class Worker;
 class WorkerClients;
 class WorkerInspectorProxy;
 
-class WorkerMessagingProxy final : public WorkerGlobalScopeProxy, public WorkerLoaderProxy {
-    WTF_MAKE_NONCOPYABLE(WorkerMessagingProxy); WTF_MAKE_FAST_ALLOCATED;
+class WorkerMessagingProxy final
+    : public WorkerGlobalScopeProxy
+    , private WorkerLoaderProxyProvider {
+    WTF_MAKE_NONCOPYABLE(WorkerMessagingProxy);
+    WTF_MAKE_FAST_ALLOCATED;
 public:
     WorkerMessagingProxy(Worker*, PassOwnPtrWillBeRawPtr<WorkerClients>);
 
     // Implementations of WorkerGlobalScopeProxy.
     // (Only use these methods in the worker object thread.)
     virtual void startWorkerGlobalScope(const KURL& scriptURL, const String& userAgent, const String& sourceCode, WorkerThreadStartMode) override;
     virtual void terminateWorkerGlobalScope() override;
     virtual void postMessageToWorkerGlobalScope(PassRefPtr<SerializedScriptValue>, PassOwnPtr<MessagePortChannelArray>) override;
     virtual bool hasPendingActivity() const override;
     virtual void workerObjectDestroyed() override;
 
     // These methods come from worker context thread via WorkerObjectProxy
     // and are called on the worker object thread (e.g. main thread).
     void postMessageToWorkerObject(PassRefPtr<SerializedScriptValue>, PassOwnPtr<MessagePortChannelArray>);
     void reportException(const String& errorMessage, int lineNumber, int columnNumber, const String& sourceURL, int exceptionId);
     void reportConsoleMessage(MessageSource, MessageLevel, const String& message, int lineNumber, const String& sourceURL);
     void postMessageToPageInspector(const String&);
     void postWorkerConsoleAgentEnabled();
     WorkerInspectorProxy* workerInspectorProxy();
     void confirmMessageFromWorkerObject(bool hasPendingActivity);
     void reportPendingActivity(bool hasPendingActivity);
     void workerGlobalScopeClosed();
     void workerThreadTerminated();
 
-    // Implementation of WorkerLoaderProxy.
-    // These methods are called on different threads to schedule loading
-    // requests and to send callbacks back to WorkerGlobalScope.
-    virtual void postTaskToLoader(PassOwnPtr<ExecutionContextTask>) override;
-    virtual bool postTaskToWorkerGlobalScope(PassOwnPtr<ExecutionContextTask>) override;
-
     void workerThreadCreated(PassRefPtr<DedicatedWorkerThread>);
 
 protected:
     virtual ~WorkerMessagingProxy();
 
 private:
     static void workerObjectDestroyedInternal(ExecutionContext*, WorkerMessagingProxy*);
     void terminateInternally();
 
+    // WorkerLoaderProxyProvider
+    // These methods are called on different threads to schedule loading
+    // requests and to send callbacks back to WorkerGlobalScope.
+    virtual void postTaskToLoader(PassOwnPtr<ExecutionContextTask>) override;
+    virtual bool postTaskToWorkerGlobalScope(PassOwnPtr<ExecutionContextTask>) override;
+
     RefPtrWillBePersistent<ExecutionContext> m_executionContext;
     OwnPtr<WorkerObjectProxy> m_workerObjectProxy;
     Worker* m_workerObject;
     bool m_mayBeDestroyed;
     RefPtr<DedicatedWorkerThread> m_workerThread;
 
     unsigned m_unconfirmedMessageCount; // Unconfirmed messages from worker object to worker thread.
     bool m_workerThreadHadPendingActivity; // The latest confirmation from worker thread reported that it was still active.
 
     bool m_askedToTerminate;
 
     Vector<OwnPtr<ExecutionContextTask>> m_queuedEarlyTasks; // Tasks are queued here until there's a thread object created.
     OwnPtr<WorkerInspectorProxy> m_workerInspectorProxy;
 
     OwnPtrWillBePersistent<WorkerClients> m_workerClients;
+
+    RefPtr<WorkerLoaderProxy> m_loaderProxy;
 };
 
 } // namespace blink
 
 #endif // WorkerMessagingProxy_h