Write new Starts/EndsWith and convert FilePath functions to StringPiece.

content/browser/download/save_package.h

Index: content/browser/download/save_package.h
diff --git a/content/browser/download/save_package.h b/content/browser/download/save_package.h
index 3507b1760b4c29e02aee251e37da9687827fcc40..071a5b7adead60a4eebbad9f4208bd2b957dd38d 100644
--- a/content/browser/download/save_package.h
+++ b/content/browser/download/save_package.h
@@ -301,9 +301,10 @@ class CONTENT_EXPORT SavePackage
   // Number of all need to be saved resources.
   size_t all_save_items_count_;
 
-  typedef std::set<base::FilePath::StringType,
-                   bool (*)(const base::FilePath::StringType&,
-                            const base::FilePath::StringType&)> FileNameSet;
+  using FileNameSet =
+      std::set<base::FilePath::StringType,
+               bool (*)(base::FilePath::StringPieceType,
+                        base::FilePath::StringPieceType)>;
   // This set is used to eliminate duplicated file names in saving directory.
   FileNameSet file_name_set_;