Create a QUIC wrapper around scoped_refptr.

net/quic/platform/impl/quic_mutex_impl.h

 // Copyright (c) 2016 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 NET_QUIC_PLATFORM_IMPL_QUIC_MUTEX_IMPL_H_
 #define NET_QUIC_PLATFORM_IMPL_QUIC_MUTEX_IMPL_H_
 
 #include "base/synchronization/lock.h"
 #include "net/quic/platform/api/quic_export.h"
 
@@ skipping 18 matching lines @@
 #endif
 
 #ifndef SCOPED_LOCKABLE
 #define SCOPED_LOCKABLE
 #endif
 
 #ifndef GUARDED_BY
 #define GUARDED_BY(x)
 #endif
 
+#ifndef SHARED_LOCKS_REQUIRED
+#define SHARED_LOCKS_REQUIRED(...)
+#endif
+
 namespace net {
 
 // A class wrapping a non-reentrant mutex.
 class QUIC_EXPORT_PRIVATE QuicLockImpl {
  public:
   QuicLockImpl() = default;
 
   // Block until lock_ is free, then acquire it exclusively.
   void WriterLock() EXCLUSIVE_LOCK_FUNCTION();
 
@@ skipping 11 matching lines @@
 
  private:
   base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicLockImpl);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_PLATFORM_IMPL_QUIC_MUTEX_IMPL_H_