Keep the module in scope when executing scripts. This prevents a crash when the

ppapi/proxy/ppb_var_deprecated_proxy.cc

Index: ppapi/proxy/ppb_var_deprecated_proxy.cc
===================================================================
--- ppapi/proxy/ppb_var_deprecated_proxy.cc	(revision 81764)
+++ ppapi/proxy/ppb_var_deprecated_proxy.cc	(working copy)
@@ -315,6 +315,13 @@
 }
 
 bool PPB_Var_Deprecated_Proxy::OnMessageReceived(const IPC::Message& msg) {
+  // Prevent the dispatcher from going away during a call to Call or other
+  // function that could mutate the DOM. This must happen OUTSIDE of
+  // the message handlers since the SerializedVars use the dispatcher upon
+  // return of the function (converting the SerializedVarReturnValue/OutParam
+  // to a SerializedVar in the destructor).
+  ScopedModuleReference death_grip(dispatcher());
+
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PPB_Var_Deprecated_Proxy, msg)
     IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBVar_HasProperty,