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

chrome/browser/extensions/extension_preference_helpers.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/extension_preference_helpers.h"
 
 #include "base/json/json_writer.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/event_router.h"
 #include "chrome/browser/extensions/extension_prefs.h"
@@ skipping 86 matching lines @@
         (*it)->HasAPIPermission(permission) &&
         (!incognito || (*it)->incognito_split_mode() ||
          extension_service->CanCrossIncognito(*it))) {
       // Inject level of control key-value.
       DictionaryValue* dict;
       bool rv = args->GetDictionary(0, &dict);
       DCHECK(rv);
       std::string level_of_control =
           GetLevelOfControl(profile, extension_id, browser_pref, incognito);
       dict->SetString(kLevelOfControlKey, level_of_control);
-      std::string json_args;
-      base::JSONWriter::Write(args, &json_args);
 
       // If the extension is in incognito split mode,
       // a) incognito pref changes are visible only to the incognito tabs
       // b) regular pref changes are visible only to the incognito tabs if the
       //    incognito pref has not alredy been set
       Profile* restrict_to_profile = NULL;
       bool from_incognito = false;
       if ((*it)->incognito_split_mode()) {
         if (incognito && extension_service->IsIncognitoEnabled(extension_id)) {
           restrict_to_profile = profile->GetOffTheRecordProfile();
         } else if (!incognito &&
                    extension_prefs->DoesExtensionControlPref(
                        extension_id,
                        browser_pref,
                        &from_incognito) &&
                    from_incognito) {
           restrict_to_profile = profile;
         }
       }
 
+      scoped_ptr<ListValue> args_copy(args->DeepCopy());
       router->DispatchEventToExtension(
-          extension_id, event_name, json_args, restrict_to_profile, GURL());
+          extension_id, event_name, args_copy.Pass(), restrict_to_profile,
+          GURL());
     }
   }
 }
 
 }  // namespace extension_preference_helpers