Track printer installations for each configuration.

chromeos/printing/printer_configuration.cc

Index: chromeos/printing/printer_configuration.cc
diff --git a/chromeos/printing/printer_configuration.cc b/chromeos/printing/printer_configuration.cc
index 9b6f66328c93af86efccb2da3a47f6a19cb1f1e6..cd3b3307e648bef855f4b8c6f90a89e1c96fba34 100644
--- a/chromeos/printing/printer_configuration.cc
+++ b/chromeos/printing/printer_configuration.cc
@@ -14,7 +14,8 @@ Printer::Printer() : source_(SRC_USER_PREFS) {
   id_ = base::GenerateGUID();
 }
 
-Printer::Printer(const std::string& id) : id_(id), source_(SRC_USER_PREFS) {
+Printer::Printer(const std::string& id, const base::Time& last_updated)
+    : id_(id), source_(SRC_USER_PREFS), last_updated_(last_updated) {
   if (id_.empty())
     id_ = base::GenerateGUID();
 }