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

webkit/plugins/npapi/webplugin_impl.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_IMPL_H_
 #define WEBKIT_PLUGINS_NPAPI_WEBPLUGIN_IMPL_H_
 
 #include <string>
 #include <map>
 #include <vector>
@@ skipping 92 matching lines @@
   virtual void CancelResource(unsigned long id);
   virtual void Invalidate();
   virtual void InvalidateRect(const gfx::Rect& rect);
   virtual NPObject* GetWindowScriptNPObject();
   virtual NPObject* GetPluginElement();
   virtual void SetCookie(const GURL& url,
                          const GURL& first_party_for_cookies,
                          const std::string& cookie);
   virtual std::string GetCookies(const GURL& url,
                                  const GURL& first_party_for_cookies);
-  virtual void OnMissingPluginStatus(int status);
-
   virtual void URLRedirectResponse(bool allow, int resource_id);
 
   // Given a (maybe partial) url, completes using the base url.
   GURL CompleteURL(const char* url);
 
   enum RoutingStatus {
     ROUTED,
     NOT_ROUTED,
     INVALID_URL,
     GENERAL_FAILURE
@@ skipping 176 matching lines @@
 
   ScopedRunnableMethodFactory<WebPluginImpl> method_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebPluginImpl);
 };
 
 }  // namespace npapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_NPAPI_WEBPLUGIN_IMPL_H_