Make V8ValueConverter.FromV8Value behave similarly to JSON.stringify

chrome/renderer/extensions/event_bindings.cc

 // Copyright (c) 2012 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 "chrome/renderer/extensions/event_bindings.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/basictypes.h"
@@ skipping 173 matching lines @@
     if (extension_id.empty())
       return v8::Integer::New(-1);
 
     scoped_ptr<base::DictionaryValue> filter;
     scoped_ptr<content::V8ValueConverter> converter(
         content::V8ValueConverter::create());
 
     base::DictionaryValue* filter_dict = NULL;
     base::Value* filter_value = converter->FromV8Value(args[1]->ToObject(),
         v8::Context::GetCurrent());
+    if (!filter_value)
+      return v8::Integer::New(-1);
     if (!filter_value->GetAsDictionary(&filter_dict)) {
       delete filter_value;
       return v8::Integer::New(-1);
     }
 
     filter.reset(filter_dict);
     extensions::EventFilter& event_filter = g_event_filter.Get();
     int id = event_filter.AddEventMatcher(event_name, ParseEventMatcher(
         filter.get()));
 
@@ skipping 125 matching lines @@
 };
 
 }  // namespace
 
 // static
 ChromeV8Extension* EventBindings::Get(Dispatcher* dispatcher) {
   return new ExtensionImpl(dispatcher);
 }
 
 }  // namespace extensions