Reland 100233 PrintPreview: Added code to identify the printer default duplex value.

Added code to identify the printer default duplex value. If we are
unable to get the default value, hide the two sided option in the preview tab.

BUG=89204
TEST=Please refer to bug description.

Original Commit: http://src.chromium.org/viewvc/chrome?view=rev&revision=100233
Try bot results are in http://codereview.chromium.org/7817013/ patch set 13.
Original Review URL: http://codereview.chromium.org/7817013/

Review URL: http://codereview.chromium.org/7859007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@100256 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/printing/print_job_constants.h b/printing/print_job_constants.h
index 99b2892..ebd63c2 100644
--- a/printing/print_job_constants.h
+++ b/printing/print_job_constants.h
@@ -49,6 +49,7 @@
 
 // Print job duplex mode values.
 enum DuplexMode {
+  UNKNOWN_DUPLEX_MODE = -1,
   SIMPLEX,
   LONG_EDGE,
   SHORT_EDGE,