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

chrome/browser/history/history_extension_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/history/history_extension_api.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/json/json_writer.h"
@@ skipping 141 matching lines @@
       NOTREACHED();
   }
 }
 
 void HistoryExtensionEventRouter::HistoryUrlVisited(
     Profile* profile,
     const history::URLVisitedDetails* details) {
   scoped_ptr<HistoryItem> history_item = GetHistoryItem(details->row);
   scoped_ptr<ListValue> args = OnVisited::Create(*history_item);
 
-  std::string json_args;
-  base::JSONWriter::Write(args.get(), &json_args);
-  DispatchEvent(profile, kOnVisited, json_args);
+  DispatchEvent(profile, kOnVisited, args.Pass());
 }
 
 void HistoryExtensionEventRouter::HistoryUrlsRemoved(
     Profile* profile,
     const history::URLsDeletedDetails* details) {
   OnVisitRemoved::Removed removed;
   removed.all_history = details->all_history;
 
   std::vector<std::string>* urls = new std::vector<std::string>();
   for (history::URLRows::const_iterator iterator = details->rows.begin();
       iterator != details->rows.end(); ++iterator) {
     urls->push_back(iterator->url().spec());
   }
   removed.urls.reset(urls);
 
   scoped_ptr<ListValue> args = OnVisitRemoved::Create(removed);
-  std::string json_args;
-  base::JSONWriter::Write(args.get(), &json_args);
-  DispatchEvent(profile, kOnVisitRemoved, json_args);
+  DispatchEvent(profile, kOnVisitRemoved, args.Pass());
 }
 
-void HistoryExtensionEventRouter::DispatchEvent(Profile* profile,
-                                                const char* event_name,
-                                                const std::string& json_args) {
+void HistoryExtensionEventRouter::DispatchEvent(
+    Profile* profile,
+    const char* event_name,
+    scoped_ptr<ListValue> event_args) {
   if (profile && profile->GetExtensionEventRouter()) {
     profile->GetExtensionEventRouter()->DispatchEventToRenderers(
-        event_name, json_args, profile, GURL(),
+        event_name, event_args.Pass(), profile, GURL(),
         extensions::EventFilteringInfo());
   }
 }
 
 void HistoryFunction::Run() {
   if (!RunImpl()) {
     SendResponse(false);
   }
 }
 
@@ skipping 197 matching lines @@
       &cancelable_consumer_,
       base::Bind(&DeleteAllHistoryFunction::DeleteComplete,
                  base::Unretained(this)));
 
   return true;
 }
 
 void DeleteAllHistoryFunction::DeleteComplete() {
   SendAsyncResponse();
 }