Rewrite simple uses of base::ListValue::Append(base::Value*) on CrOS.

chrome/browser/chromeos/file_manager/file_browser_handlers.cc

Index: chrome/browser/chromeos/file_manager/file_browser_handlers.cc
diff --git a/chrome/browser/chromeos/file_manager/file_browser_handlers.cc b/chrome/browser/chromeos/file_manager/file_browser_handlers.cc
index 013aada63706e1731ebdc4dbf62d7e5248c9a6c8..4d4985c9ab0d36cd4fb6736a661bc99e08c412e3 100644
--- a/chrome/browser/chromeos/file_manager/file_browser_handlers.cc
+++ b/chrome/browser/chromeos/file_manager/file_browser_handlers.cc
@@ -387,7 +387,7 @@ void FileBrowserHandlerExecutor::SetupPermissionsAndDispatchEvent(
       file_definition_list.get(), extension_.get(), handler_pid);
 
   std::unique_ptr<base::ListValue> event_args(new base::ListValue());
-  event_args->Append(new base::StringValue(action_id_));
+  event_args->AppendString(action_id_);
   base::DictionaryValue* details = new base::DictionaryValue();
   event_args->Append(details);
   // Get file definitions. These will be replaced with Entry instances by