Pass location and description of local printers into print preview.

printing/print_job_constants.cc

Index: printing/print_job_constants.cc
diff --git a/printing/print_job_constants.cc b/printing/print_job_constants.cc
index 6ccc4c119e291365af5a454e1728073c66e9f146..6bc5941b46affb5a5ad6db30ff52b18a948a5162 100644
--- a/printing/print_job_constants.cc
+++ b/printing/print_job_constants.cc
@@ -123,6 +123,12 @@ const char kSettingPrintableAreaHeight[] = "printableAreaHeight";
 // Printer name.
 const char kSettingPrinterName[] = "printerName";
 
+// Printer description.
+const char kSettingPrinterDescription[] = "printerDescription";
+
+// Additional printer options.
+const char kSettingPrinterOptions[] = "printerOptions";
+
 // Print to PDF option: true if selected, false if not.
 const char kSettingPrintToPDF[] = "printToPDF";