Moved the following IPC messages used by the chrome NPAPI plugin installer out of content

webkit/plugins/npapi/webplugin.h

 // Copyright (c) 2011 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 WEBKIT_PLUGINS_NPAPI_WEBPLUGIN_H_
 #define WEBKIT_PLUGINS_NPAPI_WEBPLUGIN_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 90 matching lines @@
   // reference.
   virtual NPObject* GetPluginElement() = 0;
 
   // Cookies
   virtual void SetCookie(const GURL& url,
                          const GURL& first_party_for_cookies,
                          const std::string& cookie) = 0;
   virtual std::string GetCookies(const GURL& url,
                                  const GURL& first_party_for_cookies) = 0;
 
-  // When a default plugin has downloaded the plugin list and finds it is
-  // available, it calls this method to notify the renderer. Also it will update
-  // the status when user clicks on the plugin to install.
-  virtual void OnMissingPluginStatus(int status) = 0;
-
   // Handles GetURL/GetURLNotify/PostURL/PostURLNotify requests initiated
   // by plugins.  If the plugin wants notification of the result, notify_id will
   // be non-zero.
   virtual void HandleURLRequest(const char* url,
                                 const char* method,
                                 const char* target,
                                 const char* buf,
                                 unsigned int len,
                                 int notify_id,
                                 bool popups_allowed,
@@ skipping 60 matching lines @@
   virtual void DidFinishLoading() = 0;
   virtual void DidFail() = 0;
   virtual bool IsMultiByteResponseExpected() = 0;
   virtual int ResourceId() = 0;
 };
 
 }  // namespace npapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_NPAPI_WEBPLUGIN_H_