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

chrome/browser/extensions/api/offscreen_tabs/offscreen_tabs_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/offscreen_tabs/offscreen_tabs_api.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/hash_tables.h"
@@ skipping 246 matching lines @@
 
 void OffscreenTab::Observe(int type,
                            const NotificationSource& source,
                            const NotificationDetails& details) {
   CHECK_EQ(content::NOTIFICATION_NAV_ENTRY_COMMITTED, type);
 
   DictionaryValue* changed_properties = new DictionaryValue();
   changed_properties->SetString(
       tabs_keys::kUrlKey, web_contents()->GetURL().spec());
 
-  ListValue args;
-  args.Append(Value::CreateIntegerValue(
+  scoped_ptr<ListValue> args(new ListValue());
+  args->Append(Value::CreateIntegerValue(
       ExtensionTabUtil::GetTabId(web_contents())));
-  args.Append(changed_properties);
-  args.Append(CreateValue());
-  std::string json_args;
-  base::JSONWriter::Write(&args, &json_args);
+  args->Append(changed_properties);
+  args->Append(CreateValue());
 
   // The event router only dispatches the event to renderers listening for the
   // event.
   Profile* profile = parent_tab_->tab_contents()->profile();
   profile->GetExtensionEventRouter()->DispatchEventToRenderers(
-      events::kOnOffscreenTabUpdated, json_args, profile, GURL(),
+      events::kOnOffscreenTabUpdated, args.Pass(), profile, GURL(),
       extensions::EventFilteringInfo());
 }
 
 ParentTab::ParentTab() : tab_contents_(NULL) {}
 ParentTab::~ParentTab() {}
 
 void ParentTab::Init(WebContents* web_contents,
                      const std::string& extension_id) {
   CHECK(web_contents);
 
@@ skipping 542 matching lines @@
   // async case (when a "javascript": URL is sent to a tab).
   if (!is_async)
     SendResponse(true);
 
   return true;
 }
 
 void UpdateOffscreenTabFunction::PopulateResult() {
   // There's no result associated with this callback.
 }