Add Darwin thread.h implementation.

webrtc/base/thread.h

 /*
  *  Copyright 2004 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 73 matching lines @@
   virtual ~Runnable() {}
   virtual void Run(Thread* thread) = 0;
 
  protected:
   Runnable() {}
 
  private:
   RTC_DISALLOW_COPY_AND_ASSIGN(Runnable);
 };
 
+struct ThreadInit {
+  Thread* thread;
+  Runnable* runnable;
+};
+
+
 // WARNING! SUBCLASSES MUST CALL Stop() IN THEIR DESTRUCTORS!  See ~Thread().
 
 class LOCKABLE Thread : public MessageQueue {
  public:
   // Create a new Thread and optionally assign it to the passed SocketServer.
   Thread();
   explicit Thread(SocketServer* ss);
   explicit Thread(std::unique_ptr<SocketServer> ss);
 
   // NOTE: ALL SUBCLASSES OF Thread MUST CALL Stop() IN THEIR DESTRUCTORS (or
@@ skipping 225 matching lines @@
 
  private:
   SocketServer* old_ss_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(SocketServerScope);
 };
 
 }  // namespace rtc
 
 #endif  // WEBRTC_BASE_THREAD_H_