Add function to CancelableTaskTracker and convert BootTimeLoader

chrome/browser/chromeos/boot_times_loader.h

Index: chrome/browser/chromeos/boot_times_loader.h
diff --git a/chrome/browser/chromeos/boot_times_loader.h b/chrome/browser/chromeos/boot_times_loader.h
index 691a44ffd97039d8775c48da9060d6fee87ea024..dc420e851d6810355665ccd31414112cd4a5fb01 100644
--- a/chrome/browser/chromeos/boot_times_loader.h
+++ b/chrome/browser/chromeos/boot_times_loader.h
@@ -12,7 +12,7 @@
 #include "base/callback_forward.h"
 #include "base/compiler_specific.h"
 #include "base/time.h"
-#include "chrome/browser/common/cancelable_request.h"
+#include "chrome/common/cancelable_task_tracker.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/render_widget_host.h"
@@ -22,17 +22,14 @@ namespace chromeos {
 // BootTimesLoader loads the bootimes of Chrome OS from the file system.
 // Loading is done asynchronously on the file thread. Once loaded,
 // BootTimesLoader calls back to a method of your choice with the boot times.
-// To use BootTimesLoader do the following:
+// To use BootTimesLoader, do the following:
 //
 // . In your class define a member field of type chromeos::BootTimesLoader and
-//   CancelableRequestConsumerBase.
+//   CancelableTaskTracker.
 // . Define the callback method, something like:
-//   void OnBootTimesLoader(chromeos::BootTimesLoader::Handle,
-//                             BootTimesLoader::BootTimes boot_times);
-// . When you want the version invoke: loader.GetBootTimes(&consumer, callback);
-class BootTimesLoader
-    : public CancelableRequestProvider,
-      public content::NotificationObserver {
+//   void OnBootTimesLoaded(const BootTimesLoader::BootTimes& boot_times);
+// . When you want the version invoke: loader.GetBootTimes(callback, &tracker_);
+class BootTimesLoader : public content::NotificationObserver {
  public:
   BootTimesLoader();
   virtual ~BootTimesLoader();
@@ -60,17 +57,14 @@ class BootTimesLoader
                   total(0) {}
   } BootTimes;
 
-  // Signature
-  typedef base::Callback<void(Handle, BootTimes)> GetBootTimesCallback;
-
-  typedef CancelableRequest<GetBootTimesCallback> GetBootTimesRequest;
-
   static BootTimesLoader* Get();
 
+  typedef base::Callback<void(const BootTimes&)> GetBootTimesCallback;
+
   // Asynchronously requests the info.
-  Handle GetBootTimes(
-      CancelableRequestConsumerBase* consumer,
-      const GetBootTimesCallback& callback);
+  CancelableTaskTracker::TaskId GetBootTimes(
+      const GetBootTimesCallback& callback,
+      CancelableTaskTracker* tracker);
 
   // Add a time marker for login. A timeline will be dumped to
   // /tmp/login-times-sent after login is done. If |send_to_uma| is true
@@ -119,7 +113,9 @@ class BootTimesLoader
    public:
     Backend() {}
 
-    void GetBootTimes(const scoped_refptr<GetBootTimesRequest>& request);
+    void GetBootTimesAndRunCallback(
+        const CancelableTaskTracker::IsCanceledCallback& is_canceled_cb,
+        const GetBootTimesCallback& callback);
 
    private:
     friend class base::RefCountedThreadSafe<Backend>;