Remove unused base::Thread::thread_handle() getter.

base/threading/thread.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_THREADING_THREAD_H_
 #define BASE_THREADING_THREAD_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 154 matching lines @@
   // running (e.g. before Start or after Stop have been called). Callers can
   // hold on to this even after the thread is gone; in this situation, attempts
   // to PostTask() will fail.
   scoped_refptr<SingleThreadTaskRunner> task_runner() const {
     return message_loop_ ? message_loop_->task_runner() : nullptr;
   }
 
   // Returns the name of this thread (for display in debugger too).
   const std::string& thread_name() const { return name_; }
 
-  // The native thread handle.
-  PlatformThreadHandle thread_handle() { return thread_; }
-
   // Returns the thread ID.  Should not be called before the first Start*()
   // call.  Keeps on returning the same ID even after a Stop() call. The next
   // Start*() call renews the ID.
   //
   // WARNING: This function will block if the thread hasn't started yet.
   //
   PlatformThreadId GetThreadId() const;
 
   // Returns true if the thread has been started, and not yet stopped.
   bool IsRunning() const;
@@ skipping 65 matching lines @@
   mutable WaitableEvent start_event_;
 
   friend void ThreadQuitHelper();
 
   DISALLOW_COPY_AND_ASSIGN(Thread);
 };
 
 }  // namespace base
 
 #endif  // BASE_THREADING_THREAD_H_