Use document from preview for System Dialog printing on Windows.

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 6ac461c3d6498a4e41723adde9306e84954e7490..ed4d1e2f595be980157fb9e2ab94bbfd5de4cc25 100644
--- a/printing/print_job_constants.cc
+++ b/printing/print_job_constants.cc
@@ -163,6 +163,9 @@ const char kSettingShouldPrintBackgrounds[] = "shouldPrintBackgrounds";
 // Whether to print selection only.
 const char kSettingShouldPrintSelectionOnly[] = "shouldPrintSelectionOnly";
 
+// Whether to print selection only.
+const char kSettingShowSystemDialog[] = "showSystemDialog";
+
 // Indices used to represent first preview page and complete preview document.
 const int FIRST_PAGE_INDEX = 0;
 const int COMPLETE_PREVIEW_DOCUMENT_INDEX = -1;