Track printer installations for each configuration.

chromeos/printing/printer_configuration.h

 // Copyright 2016 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 CHROMEOS_PRINTING_PRINTER_CONFIGURATION_H_
 #define CHROMEOS_PRINTING_PRINTER_CONFIGURATION_H_
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
+#include "base/time/time.h"
 #include "chromeos/chromeos_export.h"
 
 namespace chromeos {
 
 class CHROMEOS_EXPORT Printer {
  public:
   // Information needed to find the PPD file for this printer.
   //
   // If you add fields to this struct, you almost certainly will
   // want to update PpdResolver and PpdCache::GetCachePath.
@@ skipping 17 matching lines @@
 
   // The location where the printer is stored.
   enum Source {
     SRC_USER_PREFS,
     SRC_POLICY,
   };
 
   // Constructs a printer object that is completely empty.
   Printer();
 
-  // Constructs a printer object with an id.
-  explicit Printer(const std::string& id);
+  // Constructs a printer object with an |id| and a |last_updated| timestamp.
+  explicit Printer(const std::string& id, const base::Time& last_updated = {});
 
   // Copy constructor and assignment.
   Printer(const Printer& printer);
   Printer& operator=(const Printer& printer);
 
   ~Printer();
 
   const std::string& id() const { return id_; }
   void set_id(const std::string& id) { id_ = id; }
 
@@ skipping 25 matching lines @@
   void set_uuid(const std::string& uuid) { uuid_ = uuid; }
 
   // Returns true if the printer should be automatically configured using
   // IPP Everywhere.  Computed using information from |ppd_reference_| and
   // |uri_|.
   bool IsIppEverywhere() const;
 
   Source source() const { return source_; }
   void set_source(const Source source) { source_ = source; }
 
+  // Returns the timestamp for the most recent update.  Returns 0 if the
+  // printer was not created with a valid timestamp.
+  base::Time last_updated() const { return last_updated_; }
+
  private:
   // Globally unique identifier. Empty indicates a new printer.
   std::string id_;
 
   // User defined string for printer identification.
   std::string display_name_;
 
   // User defined string for additional printer information.
   std::string description_;
 
   // The manufacturer of the printer, e.g. HP
   std::string manufacturer_;
 
   // The model of the printer, e.g. OfficeJet 415
   std::string model_;
 
   // The full path for the printer. Suitable for configuration in CUPS.
   // Contains protocol, hostname, port, and queue.
   std::string uri_;
 
   // How to find the associated postscript printer description.
   PpdReference ppd_reference_;
 
   // The UUID from an autoconf protocol for deduplication. Could be empty.
   std::string uuid_;
 
   // The datastore which holds this printer.
   Source source_;
+
+  // Timestamp of most recent change.
+  base::Time last_updated_;
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_PRINTING_PRINTER_CONFIGURATION_H_