Revert of Remove NPAPI plugin from chromoting webapp.

remoting/host/chromoting_host_context.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 REMOTING_HOST_CHROMOTING_HOST_CONTEXT_H_
 #define REMOTING_HOST_CHROMOTING_HOST_CONTEXT_H_
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 31 matching lines @@
   //
   // TODO(sergeyu): Do we need a separate thread for InputInjector?
   // Can we use some other thread instead?
   scoped_refptr<AutoThreadTaskRunner> input_task_runner();
 
   // Task runner for the thread used for network IO. This thread runs
   // a libjingle message loop, and is the only thread on which
   // libjingle code may be run.
   scoped_refptr<AutoThreadTaskRunner> network_task_runner();
 
-  // Task runner for the thread that is used for the UI.
+  // Task runner for the thread that is used for the UI. In the NPAPI
+  // plugin this corresponds to the main plugin thread.
   scoped_refptr<AutoThreadTaskRunner> ui_task_runner();
 
   // Task runner for the thread used by the ScreenRecorder to capture
   // the screen.
   scoped_refptr<AutoThreadTaskRunner> video_capture_task_runner();
 
   // Task runner for the thread used to encode video streams.
   scoped_refptr<AutoThreadTaskRunner> video_encode_task_runner();
 
   scoped_refptr<net::URLRequestContextGetter> url_request_context_getter();
@@ skipping 24 matching lines @@
 
   // Serves URLRequestContexts that use the network and UI task runners.
   scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromotingHostContext);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_CHROMOTING_HOST_CONTEXT_H_