This CL fixes the document-open.html and window-open.html plugin layout tests...

webkit/glue/plugins/plugin_string_stream.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 "webkit/glue/plugins/plugin_string_stream.h"
 
 #include "googleurl/src/gurl.h"
 
 namespace NPAPI {
 
 PluginStringStream::PluginStringStream(
     PluginInstance* instance,
     const GURL& url,
     bool notify_needed,
     void* notify_data)
     : PluginStream(instance, url.spec().c_str(), notify_needed, notify_data) {
 }
 
 PluginStringStream::~PluginStringStream() {
 }
 
 void PluginStringStream::SendToPlugin(const std::string &data,
                                       const std::string &mime_type) {
+  // Protect the stream against it being destroyed or the whole plugin instance
+  // being destroyed within the plugin stream callbacks.
+  scoped_refptr<PluginStringStream> protect(this);
+
   int length = static_cast<int>(data.length());
   if (Open(mime_type, std::string(), length, 0, false)) {
     // TODO - check if it was not fully sent, and figure out a backup plan.
     int written = Write(data.c_str(), length, 0);
     NPReason reason = written == length ? NPRES_DONE : NPRES_NETWORK_ERR;
     Close(reason);
   }
 }
 
 }