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

chrome/browser/history/history_extension_api.cc

Index: chrome/browser/history/history_extension_api.cc
diff --git a/chrome/browser/history/history_extension_api.cc b/chrome/browser/history/history_extension_api.cc
index a55d0958cc4ee55c105bdb4c47ef8852a0df3aab..6f05b573f0abe28782fc03dc011dc9a64a7b2a4e 100644
--- a/chrome/browser/history/history_extension_api.cc
+++ b/chrome/browser/history/history_extension_api.cc
@@ -129,20 +129,18 @@ void HistoryExtensionEventRouter::Observe(
 void HistoryExtensionEventRouter::HistoryUrlVisited(
     Profile* profile,
     const history::URLVisitedDetails* details) {
-  ListValue args;
+  ListValue* args = new ListValue();
   DictionaryValue* dict = new DictionaryValue();
   GetHistoryItemDictionary(details->row, dict);
-  args.Append(dict);
+  args->Append(dict);
 
-  std::string json_args;
-  base::JSONWriter::Write(&args, &json_args);
-  DispatchEvent(profile, kOnVisited, json_args);
+  DispatchEvent(profile, kOnVisited, args);
 }
 
 void HistoryExtensionEventRouter::HistoryUrlsRemoved(
     Profile* profile,
     const history::URLsDeletedDetails* details) {
-  ListValue args;
+  ListValue* args = new ListValue();
   DictionaryValue* dict = new DictionaryValue();
   dict->SetBoolean(kAllHistoryKey, details->all_history);
   ListValue* urls = new ListValue();
@@ -151,19 +149,17 @@ void HistoryExtensionEventRouter::HistoryUrlsRemoved(
     urls->Append(new StringValue(iterator->url().spec()));
   }
   dict->Set(kUrlsKey, urls);
-  args.Append(dict);
+  args->Append(dict);
 
-  std::string json_args;
-  base::JSONWriter::Write(&args, &json_args);
-  DispatchEvent(profile, kOnVisitRemoved, json_args);
+  DispatchEvent(profile, kOnVisitRemoved, args);
 }
 
 void HistoryExtensionEventRouter::DispatchEvent(Profile* profile,
                                                 const char* event_name,
-                                                const std::string& json_args) {
+                                                ListValue* event_args) {
   if (profile && profile->GetExtensionEventRouter()) {
     profile->GetExtensionEventRouter()->DispatchEventToRenderers(
-        event_name, json_args, profile, GURL(),
+        event_name, event_args, profile, GURL(),
         extensions::EventFilteringInfo());
   }
 }