Refactor extension event distribution to use Values instead of JSON strings.

chrome/browser/extensions/api/downloads/downloads_api.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/browser/extensions/api/downloads/downloads_api.h"
 
 #include <algorithm>
 #include <cctype>
 #include <iterator>
 #include <set>
@@ skipping 900 matching lines @@
 void ExtensionDownloadsEventRouter::ManagerGoingDown(
     DownloadManager* manager) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   manager_->RemoveObserver(this);
   manager_ = NULL;
 }
 
 void ExtensionDownloadsEventRouter::DispatchEvent(
     const char* event_name, base::Value* arg) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  base::ListValue args;
-  args.Append(arg);
+  scoped_ptr<ListValue> args(new ListValue());
+  args->Append(arg);
   std::string json_args;
-  base::JSONWriter::Write(&args, &json_args);
+  base::JSONWriter::Write(args.get(), &json_args);
+
   profile_->GetExtensionEventRouter()->DispatchEventToRenderers(
       event_name,
-      json_args,
+      args.Pass(),
       profile_,
       GURL(),
       extensions::EventFilteringInfo());
 
   DownloadsNotificationSource notification_source;
   notification_source.event_name = event_name;
   notification_source.profile = profile_;
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_EXTENSION_DOWNLOADS_EVENT,
       content::Source<DownloadsNotificationSource>(&notification_source),
       content::Details<std::string>(&json_args));
 }