Continue to clean c_str() calls.

printing/backend/print_backend_cups.cc

Index: printing/backend/print_backend_cups.cc
diff --git a/printing/backend/print_backend_cups.cc b/printing/backend/print_backend_cups.cc
index 39a08581703eb492273aeb572b8d3386d856c0fa..66d65904777370757956d05c2fda40cc5f862b32 100644
--- a/printing/backend/print_backend_cups.cc
+++ b/printing/backend/print_backend_cups.cc
@@ -209,7 +209,7 @@ scoped_refptr<PrintBackend> PrintBackend::CreateInstanceImpl(
 
     print_backend_settings->GetInteger(kCUPSEncryption, &encryption);
   }
-  GURL print_server_url(print_server_url_str.c_str());
+  GURL print_server_url(print_server_url_str);
   return new PrintBackendCUPS(print_server_url,
                               static_cast<http_encryption_t>(encryption),
                               cups_blocking == kValueTrue);