Make various string_util functions take StringPieces instead of char[].

components/webdata/common/web_database_migration_unittest.cc

Index: components/webdata/common/web_database_migration_unittest.cc
diff --git a/components/webdata/common/web_database_migration_unittest.cc b/components/webdata/common/web_database_migration_unittest.cc
index b0925bc4d0074214756a3db3f60c58f028e608c6..aa3d0dd65a40023b66b282801a99afcdab169ea8 100644
--- a/components/webdata/common/web_database_migration_unittest.cc
+++ b/components/webdata/common/web_database_migration_unittest.cc
@@ -157,10 +157,9 @@ void CheckNoBackupData(const sql::Connection& connection,
 }
 
 std::string RemoveQuotes(const std::string& has_quotes) {
-  // SQLite quotes: http://www.sqlite.org/lang_keywords.html
-  static const char kQuotes[] = "\"[]`";
   std::string no_quotes;
-  base::RemoveChars(has_quotes, kQuotes, &no_quotes);
+  // SQLite quotes: http://www.sqlite.org/lang_keywords.html
+  base::RemoveChars(has_quotes, "\"[]`", &no_quotes);
   return no_quotes;
 }