mac: Make GetOSVersion() private to a cc file.

webrtc/base/macutils.h

 /*
  *  Copyright 2007 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 25 matching lines @@
   kMacOSPanther,       // 10.3
   kMacOSTiger,         // 10.4
   kMacOSLeopard,       // 10.5
   kMacOSSnowLeopard,   // 10.6
   kMacOSLion,          // 10.7
   kMacOSMountainLion,  // 10.8
   kMacOSMavericks,     // 10.9
   kMacOSNewer,         // 10.10+
 };
 
-bool GetOSVersion(int* major, int* minor, int* bugfix);
 MacOSVersionName GetOSVersionName();
 bool GetQuickTimeVersion(std::string* version);
 
 // Runs the given apple script. Only supports scripts that does not
 // require user interaction.
 bool RunAppleScript(const std::string& script);
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
 
 }  // namespace rtc
 
 #endif  // WEBRTC_BASE_MACUTILS_H__