Add API to set thread name

runtime/vm/os_thread.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_H_
 #define VM_OS_THREAD_H_
 
 #include "platform/globals.h"
 #include "vm/allocation.h"
 #include "vm/globals.h"
@@ skipping 57 matching lines @@
 
   ThreadId trace_id() const {
     ASSERT(trace_id_ != OSThread::kInvalidThreadJoinId);
     return trace_id_;
   }
 
   const char* name() const {
     return name_;
   }
 
+  void SetName(const char* name);
+
   void set_name(const char* name) {
     ASSERT(OSThread::Current() == this);
     ASSERT(name_ == NULL);
     ASSERT(name != NULL);
     name_ = strdup(name);
   }
 
   Mutex* timeline_block_lock() const {
     return timeline_block_lock_;
   }
@@ skipping 255 matching lines @@
   friend class SafepointMonitorLocker;
   friend void Dart_TestMonitor();
   DISALLOW_COPY_AND_ASSIGN(Monitor);
 };
 
 
 }  // namespace dart
 
 
 #endif  // VM_OS_THREAD_H_