The webkit java applet creation code passes in the baseURL which is typically...

webkit/glue/webframeloaderclient_impl.cc

 // 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.
 
 #include "config.h"
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 
@@ skipping 1401 matching lines @@
 // This method gets called when a plugin is put in place of html content
 // (e.g., acrobat reader).
 void WebFrameLoaderClient::redirectDataToPlugin(Widget* pluginWidget) {
   plugin_widget_ = static_cast<WebPluginContainer*>(pluginWidget);
   DCHECK(plugin_widget_ != NULL);
 }
 
 Widget* WebFrameLoaderClient::createJavaAppletWidget(
                                            const IntSize& size,
                                            HTMLAppletElement* element,
-                                           const KURL& url,
+                                           const KURL& /* base_url */,
                                            const Vector<String>& param_names,
                                            const Vector<String>& param_values) {
-  return createPlugin(size, element, url, param_names, param_values,
+  return createPlugin(size, element, KURL(), param_names, param_values,
       "application/x-java-applet", false);
 }
 
 ObjectContentType WebFrameLoaderClient::objectContentType(
     const KURL& url,
     const String& explicit_mime_type) {
   // This code is based on Apple's implementation from
   // WebCoreSupport/WebFrameBridge.mm.
 
   String mime_type = explicit_mime_type;
@@ skipping 69 matching lines @@
 
   std::string offset_str = url.ExtractFileName();
   int offset;
   if (!StringToInt(offset_str, &offset))
     return;
 
   WebViewDelegate* d = webframe_->GetWebViewImpl()->delegate();
   if (d)
     d->NavigateBackForwardSoon(offset);
 }