Do not touch a NPStream object when it is already destructed....

webkit/glue/plugins/plugin_instance.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 "build/build_config.h"
 
 #include "webkit/glue/plugins/plugin_instance.h"
 
 #include "base/file_util.h"
 #include "base/message_loop.h"
@@ skipping 189 matching lines @@
   if (npp_functions_->newstream != 0) {
       return npp_functions_->newstream(npp_, type, stream, seekable, stype);
   }
   return NPERR_INVALID_FUNCTABLE_ERROR;
 }
 
 NPError PluginInstance::NPP_DestroyStream(NPStream *stream, NPReason reason) {
   DCHECK(npp_functions_ != 0);
   DCHECK(npp_functions_->destroystream != 0);
 
-  if (stream == NULL || (stream->ndata == NULL) ||
-      !IsValidStream(stream))
+  if (stream == NULL || !IsValidStream(stream) || (stream->ndata == NULL))
     return NPERR_INVALID_INSTANCE_ERROR;
 
   if (npp_functions_->destroystream != 0) {
     NPError result = npp_functions_->destroystream(npp_, stream, reason);
     stream->ndata = NULL;
     return result;
   }
   return NPERR_INVALID_FUNCTABLE_ERROR;
 }
 
@@ skipping 262 matching lines @@
           stream->url, range_info.c_str(),
           reinterpret_cast<intptr_t>(plugin_stream),
           plugin_stream->notify_needed(),
           reinterpret_cast<intptr_t>(plugin_stream->notify_data()));
       break;
     }
   }
 }
 
 }  // namespace NPAPI