Enable clang warning for ignored attributes.

ppapi/shared_impl/ppb_tcp_socket_shared.h

 // 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.
 
 #ifndef PPAPI_SHARED_IMPL_PPB_TCP_SOCKET_SHARED_H_
 #define PPAPI_SHARED_IMPL_PPB_TCP_SOCKET_SHARED_H_
 
 #include "ppapi/shared_impl/ppapi_shared_export.h"
 
 namespace ppapi {
@@ skipping 35 matching lines @@
 
   bool IsConnected() const;
   bool IsBound() const;
 
  private:
   StateType state_;
   TransitionType pending_transition_;
 };
 
 // TCP socket API versions.
-enum PPAPI_SHARED_EXPORT TCPSocketVersion {
+enum TCPSocketVersion {
   // PPB_TCPSocket_Private.
   TCP_SOCKET_VERSION_PRIVATE,
   // PPB_TCPSocket v1.0.
   TCP_SOCKET_VERSION_1_0,
   // PPB_TCPSocket v1.1 or above.
   TCP_SOCKET_VERSION_1_1_OR_ABOVE
 };
 
 }  // namespace ppapi
 
 #endif  // PPAPI_SHARED_IMPL_PPB_TCP_SOCKET_SHARED_H_