Added PrintingContext::Delegate to get parent view handle and application locale.

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 8ac5db4f7213f7f55ff8d4ddddca9ed9118134e1..6ac461c3d6498a4e41723adde9306e84954e7490 100644
--- a/printing/print_job_constants.cc
+++ b/printing/print_job_constants.cc
@@ -12,6 +12,12 @@ const char kIsFirstRequest[] = "isFirstRequest";
 // Unique ID sent along every preview request.
 const char kPreviewRequestID[] = "requestID";
 
+// Unique ID of Print Preview initiator host.
+const char kPreviewInitiatorHostId[] = "previewInitiatorHostId";
+
+// Routing ID of Print Preview initiator.
+const char kPreviewInitiatorRoutingId[] = "previewInitiatorRoutingId";
+
 // Unique ID to identify a print preview UI.
 const char kPreviewUIID[] = "previewUIID";