Replace ToLower calls to the new format

chrome/browser/media_galleries/fileapi/media_path_filter.cc

Index: chrome/browser/media_galleries/fileapi/media_path_filter.cc
diff --git a/chrome/browser/media_galleries/fileapi/media_path_filter.cc b/chrome/browser/media_galleries/fileapi/media_path_filter.cc
index 5b27f1019ab286700e79dd1abbbececbc51b89b9..d7d41e69457bbce18a0c5bedf88eb421f9c78525 100644
--- a/chrome/browser/media_galleries/fileapi/media_path_filter.cc
+++ b/chrome/browser/media_galleries/fileapi/media_path_filter.cc
@@ -152,8 +152,7 @@ bool MediaPathFilter::Match(const base::FilePath& path) {
 MediaGalleryScanFileType MediaPathFilter::GetType(const base::FilePath& path) {
   EnsureInitialized();
   MediaFileExtensionMap::const_iterator it =
-      media_file_extensions_map_.find(
-          base::StringToLowerASCII(path.Extension()));
+      media_file_extensions_map_.find(base::ToLowerASCII(path.Extension()));
   if (it == media_file_extensions_map_.end())
     return MEDIA_GALLERY_SCAN_FILE_TYPE_UNKNOWN;
   return static_cast<MediaGalleryScanFileType>(it->second);