Remove unneeded #defines from libjingle_xmpp.

jingle/glue/chrome_async_socket.h

 // Copyright (c) 2012 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.
 //
 // An implementation of buzz::AsyncSocket that uses Chrome sockets.
 
 #ifndef JINGLE_GLUE_CHROME_ASYNC_SOCKET_H_
 #define JINGLE_GLUE_CHROME_ASYNC_SOCKET_H_
 
-#if !defined(FEATURE_ENABLE_SSL)
-#error ChromeAsyncSocket expects FEATURE_ENABLE_SSL to be defined
-#endif
-
 #include <stddef.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 184 matching lines @@
   size_t write_end_;
 
   base::WeakPtrFactory<ChromeAsyncSocket> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeAsyncSocket);
 };
 
 }  // namespace jingle_glue
 
 #endif  // JINGLE_GLUE_CHROME_ASYNC_SOCKET_H_