Instead of ArrayBuffer, pass blob with printerProvider.onPrintRequested

extensions/browser/api/printer_provider/printer_provider_print_job.h

 // Copyright 2015 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 EXTENSIONS_BROWSER_API_PRINTER_PROVIDER_PRINTER_PROVIDER_PRINT_JOB_H_
 #define EXTENSIONS_BROWSER_API_PRINTER_PROVIDER_PRINTER_PROVIDER_PRINT_JOB_H_
 
 #include <string>
 
-#include "base/macros.h"
+#include "base/files/file.h"
+#include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/ref_counted_memory.h"
 
 namespace extensions {
 
 // Struct describing print job that should be forwarded to an extension via
 // chrome.printerProvider.onPrintRequested event.
+// TODO(tbarzic): This should probably be a class and have some methods, e.g.
+// whether the job is initialized and whether the data is described using a file
+// or bytes.
 struct PrinterProviderPrintJob {
   PrinterProviderPrintJob();
   ~PrinterProviderPrintJob();
 
   // The id of the printer that should handle the print job. The id is
   // formatted as <extension_id>:<printer_id>, where <extension_id> is the
   // id of the extension that manages the printer, and <printer_id> is
   // the the printer's id within the extension (as reported via
   // chrome.printerProvider.onGetPrintersRequested event callback).
   std::string printer_id;
 
   // The print job ticket.
   std::string ticket_json;
 
   // Content type of the document that should be printed.
   std::string content_type;
 
-  // The document data that should be printed.
+  // The document data that should be printed. Should be NULL if document data
+  // is kept in a file.
   scoped_refptr<base::RefCountedMemory> document_bytes;
 
- private:
-  DISALLOW_COPY_AND_ASSIGN(PrinterProviderPrintJob);
+  // Path of the file which contains data to be printed. Should be set only if
+  // |document_bytes| are NULL.
+  base::FilePath document_path;
+
+  // Information about the file which contains data to be printed. Should be
+  // set only if |document_path| is set.
+  base::File::Info file_info;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_PRINTER_PROVIDER_PRINTER_PROVIDER_PRINT_JOB_H_