Add early-injection capability to user scripts. I haven't yet

chrome/renderer/render_view.h

 // Copyright (c) 2006-2008 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 CHROME_RENDERER_RENDER_VIEW_H_
 #define CHROME_RENDERER_RENDER_VIEW_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 197 matching lines @@
                                          const GURL& dest_url,
                                          unsigned int delay_seconds,
                                          unsigned int fire_date);
   virtual void DidCancelClientRedirect(WebView* webview,
                                        WebFrame* frame);
   virtual void DidCompleteClientRedirect(WebView* webview,
                                          WebFrame* frame,
                                          const GURL& source);
 
   virtual void WindowObjectCleared(WebFrame* webframe);
+  virtual void DocumentElementAvailable(WebFrame* webframe);
+
   virtual WindowOpenDisposition DispositionForNavigationAction(
       WebView* webview,
       WebFrame* frame,
       const WebRequest* request,
       WebNavigationType type,
       WindowOpenDisposition disposition,
       bool is_redirect);
 
   virtual WebView* CreateWebView(WebView* webview, bool user_gesture);
   virtual WebWidget* CreatePopupWidget(WebView* webview, bool activatable);
@@ skipping 513 matching lines @@
   // Time in seconds of the delay between syncing page state such as form
   // elements and scroll position. This timeout allows us to avoid spamming the
   // browser process with every little thing that changes. This normally doesn't
   // change but is overridden by tests.
   int delay_seconds_for_form_state_sync_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderView);
 };
 
 #endif  // CHROME_RENDERER_RENDER_VIEW_H_