Add function to CancelableTaskTracker and convert BootTimeLoader

chrome/browser/chromeos/login/version_info_updater.h

Index: chrome/browser/chromeos/login/version_info_updater.h
diff --git a/chrome/browser/chromeos/login/version_info_updater.h b/chrome/browser/chromeos/login/version_info_updater.h
index fa458c7d6763ee894f9387d219c4f0c40b98e42d..e61143a03341d66f60ec3a622a8c84a3bd050203 100644
--- a/chrome/browser/chromeos/login/version_info_updater.h
+++ b/chrome/browser/chromeos/login/version_info_updater.h
@@ -75,11 +75,9 @@ class VersionInfoUpdater : public policy::CloudPolicySubsystem::Observer,
   // Callback from chromeos::VersionLoader giving the version.
   void OnVersion(VersionLoader::Handle handle, const std::string& version);
   // Callback from chromeos::InfoLoader giving the boot times.
-  void OnBootTimes(
-      BootTimesLoader::Handle handle, BootTimesLoader::BootTimes boot_times);
+  void OnBootTimes(const BootTimesLoader::BootTimes& boot_times);
   // Null callback from chromeos::InfoLoader.
-  void OnBootTimesNoop(
-      BootTimesLoader::Handle handle, BootTimesLoader::BootTimes boot_times);
+  void OnBootTimesNoop(const BootTimesLoader::BootTimes& boot_times);
 
   // Handles asynchronously loading the version.
   VersionLoader version_loader_;
@@ -88,8 +86,8 @@ class VersionInfoUpdater : public policy::CloudPolicySubsystem::Observer,
 
   // Handles asynchronously loading the boot times.
   BootTimesLoader boot_times_loader_;
-  // Used to request the boot times.
-  CancelableRequestConsumer boot_times_consumer_;
+  // Used to request boot times.
+  CancelableTaskTracker tracker_;
 
   // Information pieces for version label.
   std::string version_text_;