Refactoring: de-couple Extensions from "script injection System" [render side]:2

extensions/renderer/user_script_set.cc

 // 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.
 
 #include "extensions/renderer/user_script_set.h"
 
 #include "base/memory/ref_counted.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/renderer/render_thread.h"
 #include "extensions/common/extension.h"
@@ skipping 199 matching lines @@
 
   bool inject_css = !script->css_scripts().empty() &&
                     run_location == UserScript::DOCUMENT_START;
   bool inject_js =
       !script->js_scripts().empty() && script->run_location() == run_location;
   if (inject_css || inject_js) {
     injection.reset(new ScriptInjection(
         injector.Pass(),
         web_frame->toWebLocalFrame(),
         host_id,
-        // TODO(hanxi): store and obtain the instance id from the UserScript.
-        HostID::kDefaultInstanceId,
+        script->consumer_instance_info(),
         run_location,
         tab_id));
   }
   return injection.Pass();
 }
 
 }  // namespace extensions