Revert r95841 due to failing media_unittests on linux_shared bot.

media/base/message_loop_factory_impl.h

 // Copyright (c) 2011 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.
 
 #ifndef MEDIA_BASE_MESSAGE_LOOP_FACTORY_IMPL_H_
 #define MEDIA_BASE_MESSAGE_LOOP_FACTORY_IMPL_H_
 
 #include <map>
 #include <string>
 
 #include "base/threading/thread.h"
 #include "media/base/message_loop_factory.h"
 
 namespace media {
 
-class MEDIA_EXPORT MessageLoopFactoryImpl : public MessageLoopFactory {
+class MessageLoopFactoryImpl : public MessageLoopFactory {
  public:
   MessageLoopFactoryImpl();
 
   // MessageLoopFactory methods.
   virtual MessageLoop* GetMessageLoop(const std::string& name);
   virtual scoped_refptr<base::MessageLoopProxy> GetMessageLoopProxy(
       const std::string& name);
 
  protected:
   virtual ~MessageLoopFactoryImpl();
 
  private:
   // Lock used to serialize access for the following data members.
   base::Lock lock_;
 
   typedef std::map<std::string, base::Thread*> ThreadMap;
   ThreadMap thread_map_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageLoopFactoryImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MESSAGE_LOOP_FACTORY_IMPL_H_