Remove static mutexes/monitors from dart:io.

runtime/bin/secure_socket.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef BIN_SECURE_SOCKET_H_
 #define BIN_SECURE_SOCKET_H_
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
@@ skipping 72 matching lines @@
   static void InitializeLibrary(const char* certificate_database,
                                 const char* password,
                                 bool use_builtin_root_certificates,
                                 bool report_duplicate_initialization = true);
   static Dart_Port GetServicePort();
 
  private:
   static const int kMemioBufferSize = 20 * KB;
   static bool library_initialized_;
   static const char* password_;
-  static dart::Mutex mutex_;  // To protect library initialization.
+  static dart::Mutex* mutex_;  // To protect library initialization.
   static NativeService filter_service_;
 
   uint8_t* buffers_[kNumBuffers];
   int buffer_size_;
   int encrypted_buffer_size_;
   Dart_PersistentHandle string_start_;
   Dart_PersistentHandle string_length_;
   Dart_PersistentHandle dart_buffer_objects_[kNumBuffers];
   Dart_PersistentHandle handshake_complete_;
   Dart_PersistentHandle bad_certificate_callback_;
   bool in_handshake_;
   bool is_server_;
   char* client_certificate_name_;
   PRFileDesc* filter_;
 
   static bool isBufferEncrypted(int i) {
     return static_cast<BufferIndex>(i) >= kFirstEncrypted;
   }
   void InitializeBuffers(Dart_Handle dart_this);
   void InitializePlatformData();
 
   DISALLOW_COPY_AND_ASSIGN(SSLFilter);
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_SECURE_SOCKET_H_