Rolf Eike Beer authored Jan 15, 2014 and Brad King committed Jan 16, 2014

Most callers already have a std::string, on which they called c_str() to pass it
into these methods, which internally converted it back to std::string. Pass a
std::string directly to these methods now, avoiding all these conversions.
Those methods that only pass in a const char* will get the conversion to
std::string now only once.