chrome.bluetooth API improvements.

extensions/browser/api/async_api_function.h

 // Copyright 2014 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 EXTENSIONS_BROWSER_API_ASYNC_API_FUCTION_H_
 #define EXTENSIONS_BROWSER_API_ASYNC_API_FUCTION_H_
 
 #include "content/public/browser/browser_thread.h"
 #include "extensions/browser/extension_function.h"
 
@@ skipping 24 matching lines @@
   // Notify AsyncIOApiFunction that the work is completed
   void AsyncWorkCompleted();
 
   // Respond. Guaranteed to happen on UI thread.
   virtual bool Respond() = 0;
 
   // ExtensionFunction::RunImpl()
   virtual bool RunImpl() OVERRIDE;
 
  protected:
+  content::BrowserThread::ID work_thread_id() const { return work_thread_id_; }
   void set_work_thread_id(content::BrowserThread::ID work_thread_id) {
     work_thread_id_ = work_thread_id;
   }
 
  private:
   void WorkOnWorkThread();
   void RespondOnUIThread();
 
   // If you don't want your Work() method to happen on the IO thread, then set
   // this to the thread that you do want, preferably in Prepare().
   content::BrowserThread::ID work_thread_id_;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_ASYNC_API_FUCTION_H_