VM: Small clean up and const-ness fix for Thread/OSThread constants.

runtime/vm/os_thread_android.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 VM_OS_THREAD_ANDROID_H_
 #define VM_OS_THREAD_ANDROID_H_
 
 #if !defined(VM_OS_THREAD_H_)
 #error Do not include os_thread_android.h directly; use os_thread.h instead.
 #endif
 
 #include <pthread.h>
 
 #include "platform/assert.h"
 #include "platform/globals.h"
 
 namespace dart {
 
 typedef pthread_key_t ThreadLocalKey;
 typedef pid_t ThreadId;
 typedef pthread_t ThreadJoinId;
 
+
+static const ThreadLocalKey kUnsetThreadLocalKey =
+    static_cast<pthread_key_t>(-1);
+
+
 class ThreadInlineImpl {
  private:
   ThreadInlineImpl() {}
   ~ThreadInlineImpl() {}
 
   static uword GetThreadLocal(ThreadLocalKey key) {
-    static ThreadLocalKey kUnsetThreadLocalKey = static_cast<pthread_key_t>(-1);
     ASSERT(key != kUnsetThreadLocalKey);
     return reinterpret_cast<uword>(pthread_getspecific(key));
   }
 
   friend class OSThread;
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(ThreadInlineImpl);
 };
 
@@ skipping 27 matching lines @@
 
   friend class Monitor;
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(MonitorData);
 };
 
 }  // namespace dart
 
 #endif  // VM_OS_THREAD_ANDROID_H_