Move global_descriptors to base/posix.

base/posix/global_descriptors.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.
 
-#ifndef BASE_GLOBAL_DESCRIPTORS_POSIX_H_
-#define BASE_GLOBAL_DESCRIPTORS_POSIX_H_
+#ifndef BASE_POSIX_GLOBAL_DESCRIPTORS_H_
+#define BASE_POSIX_GLOBAL_DESCRIPTORS_H_
 
 #include "build/build_config.h"
 
 #include <vector>
 #include <utility>
 
 #include <stdint.h>
 
 #include "base/memory/singleton.h"
 
@@ skipping 43 matching lines @@
  private:
   friend struct DefaultSingletonTraits<GlobalDescriptors>;
   GlobalDescriptors();
   ~GlobalDescriptors();
 
   Mapping descriptors_;
 };
 
 }  // namespace base
 
-#endif  // BASE_GLOBAL_DESCRIPTORS_POSIX_H_
+#endif  // BASE_POSIX_GLOBAL_DESCRIPTORS_H_