Add job id to JobEventDetails.

printing/printing_context.h

 // 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.
 
 #ifndef PRINTING_PRINTING_CONTEXT_H_
 #define PRINTING_PRINTING_CONTEXT_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 107 matching lines @@
   // implement this method to create an object of their implementation.
   static std::unique_ptr<PrintingContext> Create(Delegate* delegate);
 
   void set_margin_type(MarginType type);
   void set_is_modifiable(bool is_modifiable);
 
   const PrintSettings& settings() const {
     return settings_;
   }
 
+  int job_id() const { return job_id_; }
+
  protected:
   explicit PrintingContext(Delegate* delegate);
 
   // Reinitializes the settings for object reuse.
   void ResetSettings();
 
   // Does bookkeeping when an error occurs.
   PrintingContext::Result OnError();
 
   // Complete print context settings.
   PrintSettings settings_;
 
   // Printing context delegate.
   Delegate* delegate_;
 
   // Is a print job being done.
   volatile bool in_print_job_;
 
   // Did the user cancel the print job.
   volatile bool abort_printing_;
 
+  // The job id for the current job. The value is 0 if no jobs are active.
+  int job_id_;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(PrintingContext);
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_PRINTING_CONTEXT_H_