Adopt standard style.

test/output_test.h

@@ -77,7 +77,7 @@ struct ResultsCheckerEntry {
   std::string name;
   std::map< std::string, std::string > values;
 
-  ResultsCheckerEntry(std::string const& n) : name(n) {}
+  ResultsCheckerEntry(const std::string& n) : name(n) {}
 
   int NumThreads() const;
 

test/output_test_helper.cc

@@ -183,7 +183,7 @@ class ResultsChecker {
   void SetHeader_(const std::string& csv_header);
   void SetValues_(const std::string& entry_csv_line);
 
-  std::vector< std::string > SplitCsv_(std::string const& line);
+  std::vector< std::string > SplitCsv_(const std::string& line);
 
 };
 
@@ -263,7 +263,7 @@ void ResultsChecker::SetValues_(const std::string& entry_csv_line) {
 }
 
 // a quick'n'dirty csv splitter (eliminating quotes)
-std::vector< std::string > ResultsChecker::SplitCsv_(std::string const& line) {
+std::vector< std::string > ResultsChecker::SplitCsv_(const std::string& line) {
   std::vector< std::string > out;
   if(line.empty()) return out;
   if(!field_names.empty()) out.reserve(field_names.size());