Print Preview: Associating preview requests and responses using an identifier

printing/print_job_constants.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "printing/print_job_constants.h"
 
 namespace printing {
 
+// Unique ID sent along every preview request.
+const char kPreviewRequestID[] = "requestID";
+
 // Print using cloud print: true if selected, false if not.
 const char kSettingCloudPrintId[] = "cloudPrintID";
 
 // Print job setting 'collate'.
 const char kSettingCollate[] = "collate";
 
 // Print out color: true for color, false for grayscale.
 const char kSettingColor[] = "color";
 
 // Number of copies.
@@ skipping 17 matching lines @@
 // The last page of a page range. (1-based)
 const char kSettingPageRangeTo[] = "to";
 
 // Printer name.
 const char kSettingPrinterName[] = "printerName";
 
 // Print to PDF option: true if selected, false if not.
 const char kSettingPrintToPDF[] = "printToPDF";
 
 }  // namespace printing