Add vendor id and custom display name to media selection

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 832f700b6d4ee0164479ed39074c757bbc511249..8ac5db4f7213f7f55ff8d4ddddca9ed9118134e1 100644
--- a/printing/print_job_constants.cc
+++ b/printing/print_job_constants.cc
@@ -86,6 +86,9 @@ const char kSettingMediaSizeHeightMicrons[] = "height_microns";
 // Key that specifies the requested media width in microns.
 const char kSettingMediaSizeWidthMicrons[] = "width_microns";
 
+// Key that specifies the requested media platform specific vendor id.
+const char kSettingMediaSizeVendorId[] = "vendor_id";
+
 // Key that specifies the bottom margin of the page.
 const char kSettingMarginBottom[] = "marginBottom";