Add paper size reporting for CUPS printers (to let user to select one in the Print Preview).

printing/backend/print_backend.h

 // Copyright (c) 2012 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.
 
 #ifndef PRINTING_BACKEND_PRINT_BACKEND_H_
 #define PRINTING_BACKEND_PRINT_BACKEND_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 34 matching lines @@
 
   bool duplex_capable;
   DuplexMode duplex_default;
 
   bool color_changeable;
   bool color_default;
   ColorModel color_model;
   ColorModel bw_model;
 
   struct Paper {
-    std::string name;
+    std::string display_name;
+    std::string vendor_id;
     gfx::Size size_um;
   };
   std::vector<Paper> papers;
   Paper default_paper;
 
   std::vector<gfx::Size> dpis;
   gfx::Size default_dpi;
 };
 
 struct PRINTING_EXPORT PrinterCapsAndDefaults {
@@ skipping 49 matching lines @@
       const base::DictionaryValue* print_backend_settings);
 
  protected:
   friend class base::RefCountedThreadSafe<PrintBackend>;
   virtual ~PrintBackend();
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_BACKEND_PRINT_BACKEND_H_