2112 function BrowserViewSourceOfDocument(aDocument)
2113 {
2114   var pageCookie;
2115   var webNav;
2116 
2117   // Get the document charset
2118   var docCharset = "charset=" + aDocument.characterSet;
2119 
2120   // Get the nsIWebNavigation associated with the document
2121   try {
2122       var win;
2123       var ifRequestor;
2124 
2125       // Get the DOMWindow for the requested document.  If the DOMWindow
2126       // cannot be found, then just use the content window...
2127       //
2128       // XXX:  This is a bit of a hack...
2129       win = aDocument.defaultView;
2130       if (win == window) {
2131         win = content;
2132       }
2133       ifRequestor = win.QueryInterface(Components.interfaces.nsIInterfaceRequestor);
2134 
2135       webNav = ifRequestor.getInterface(nsIWebNavigation);
2136   } catch(err) {
2137       // If nsIWebNavigation cannot be found, just get the one for the whole
2138       // window...
2139       webNav = gBrowser.webNavigation;
2140   }
2141   //
2142   // Get the 'PageDescriptor' for the current document. This allows the
2143   // view-source to access the cached copy of the content rather than
2144   // refetching it from the network...
2145   //
2146   try{
2147     var PageLoader = webNav.QueryInterface(Components.interfaces.nsIWebPageDescriptor);
2148 
2149     pageCookie = PageLoader.currentDescriptor;
2150   } catch(err) {
2151     // If no page descriptor is available, just use the view-source URL...
2152   }
2153 
2154   top.gViewSourceUtils.viewSource(webNav.currentURI.spec, pageCookie, aDocument);
2155 }