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 ee11af98a133a2f3a843cac693c246fe6b26740b..54d77939cd02ae0d7b6daf6c010d22196fd019c1 100644
--- a/chrome/browser/history/history_extension_api.cc
+++ b/chrome/browser/history/history_extension_api.cc
@@ -159,9 +159,7 @@ void HistoryExtensionEventRouter::HistoryUrlVisited(
   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(
@@ -178,17 +176,16 @@ void HistoryExtensionEventRouter::HistoryUrlsRemoved(
   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());
   }
 }