Track printer installations for each configuration.

chromeos/printing/printer_configuration.h

Index: chromeos/printing/printer_configuration.h
diff --git a/chromeos/printing/printer_configuration.h b/chromeos/printing/printer_configuration.h
index 27f047bdb93e39bca6b49c6b55131a04df2dc48a..81a59e0c2a63c17af58533a4baa8b76444f44d13 100644
--- a/chromeos/printing/printer_configuration.h
+++ b/chromeos/printing/printer_configuration.h
@@ -9,6 +9,7 @@
 #include <string>
 
 #include "base/macros.h"
+#include "base/time/time.h"
 #include "chromeos/chromeos_export.h"
 
 namespace chromeos {
@@ -47,7 +48,7 @@ class CHROMEOS_EXPORT Printer {
   Printer();
 
   // Constructs a printer object with an id.
-  explicit Printer(const std::string& id);
+  explicit Printer(const std::string& id, const base::Time& last_updated = {});

[Lei Zhang, 2017/05/08 21:42:48]

Does the second parameter have to be optional? I see many of the calls to this
constructor have been updated to pass in the second argument. Are there any
callers left that don't? The DCHECK in RecommendedPrinterToPrinter() makes me
wonder.

[Lei Zhang, 2017/05/08 21:42:48]

No longer explict.

[skau, 2017/05/09 00:52:01]

There are a number of instances where we don't provide the last_updated time as
we want that to be determined by the PrintersManager so it reflects sync data
accurately.

Since there is only one required argument, the linter recommends that the
constructor is still explicit.

 
   // Copy constructor and assignment.
   Printer(const Printer& printer);
@@ -93,6 +94,10 @@ class CHROMEOS_EXPORT Printer {
   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_;
@@ -121,6 +126,9 @@ class CHROMEOS_EXPORT Printer {
 
   // The datastore which holds this printer.
   Source source_;
+
+  // Timestamp of most recent change.
+  base::Time last_updated_;
 };
 
 }  // namespace chromeos