mac: Prepare for -Wunused-functions.

chrome/browser/extensions/api/developer_private/developer_private_api.cc

Index: chrome/browser/extensions/api/developer_private/developer_private_api.cc
diff --git a/chrome/browser/extensions/api/developer_private/developer_private_api.cc b/chrome/browser/extensions/api/developer_private/developer_private_api.cc
index 588f188bec1a9c2ffe016b703f87fa120c9f70ee..fb464668da21239c58c30821b38bac7f2678b31f 100644
--- a/chrome/browser/extensions/api/developer_private/developer_private_api.cc
+++ b/chrome/browser/extensions/api/developer_private/developer_private_api.cc
@@ -125,18 +125,6 @@ GURL ToDataURL(const base::FilePath& path, developer_private::ItemType type) {
   return GetImageURLFromData(contents);
 }
 
-std::vector<base::FilePath> ListFolder(const base::FilePath path) {
-  base::FileEnumerator files(path, false,
-      base::FileEnumerator::DIRECTORIES | base::FileEnumerator::FILES);
-  std::vector<base::FilePath> paths;
-
-  for (base::FilePath current_path = files.Next(); !current_path.empty();
-       current_path = files.Next()) {
-    paths.push_back(current_path);
-  }
-  return paths;
-}
-
 bool ValidateFolderName(const base::FilePath::StringType& name) {
   base::FilePath::StringType name_sanitized(name);
   file_util::ReplaceIllegalCharactersInPath(&name_sanitized, '_');