Cleaned up some constants for stats reading

chrome/browser/chromeos/browser_notification_observers.cc

Index: chrome/browser/chromeos/browser_notification_observers.cc
diff --git a/chrome/browser/chromeos/browser_notification_observers.cc b/chrome/browser/chromeos/browser_notification_observers.cc
index 366e6543a6f1d4858ad98e47f808737198c65b46..f63ade1910dbc05aa1d5e2fd27e3875992d2b470 100644
--- a/chrome/browser/chromeos/browser_notification_observers.cc
+++ b/chrome/browser/chromeos/browser_notification_observers.cc
@@ -8,23 +8,10 @@
 
 #include "base/file_util.h"
 #include "chrome/browser/chrome_thread.h"
+#include "chrome/browser/chromeos/boot_times_loader.h"
 #include "chrome/browser/chromeos/login/authentication_notification_details.h"
 #include "chrome/common/notification_service.h"
 
-namespace {
-
-// Static function that records uptime in /proc/uptime to tmp for metrics use.
-void RecordUptime(const std::string& filename) {
-  std::string uptime;
-  const FilePath proc_uptime = FilePath("/proc/uptime");
-  const FilePath uptime_output = FilePath(filename);
-
-  if (file_util::ReadFileToString(proc_uptime, &uptime))
-    file_util::WriteFile(uptime_output, uptime.data(), uptime.size());
-}
-
-}  // namespace
-
 namespace chromeos {
 
 InitialTabNotificationObserver::InitialTabNotificationObserver() {
@@ -40,13 +27,9 @@ void InitialTabNotificationObserver::Observe(
     const NotificationSource& source,
     const NotificationDetails& details) {
   // Only log for first tab to render.  Make sure this is only done once.
-  if (type == NotificationType::LOAD_START &&
-      num_tabs_.GetNext() == 0) {
+  if (type == NotificationType::LOAD_START && num_tabs_.GetNext() == 0) {
     // If we can't post it, it doesn't matter.
-    ChromeThread::PostTask(
-        ChromeThread::FILE, FROM_HERE,
-        NewRunnableFunction(RecordUptime,
-                            std::string("/tmp/uptime-chrome-first-render")));
+    BootTimesLoader::RecordCurrentStats("chrome-first-render");
     registrar_.Remove(this, NotificationType::LOAD_START,
                       NotificationService::AllSources());
   }
@@ -67,9 +50,7 @@ void LogLoginSuccessObserver::Observe(NotificationType type,
   Details<AuthenticationNotificationDetails> auth_details(details);
   if (auth_details->success()) {
     // If we can't post it, it doesn't matter.
-    ChromeThread::PostTask(ChromeThread::FILE, FROM_HERE,
-                           NewRunnableFunction(RecordUptime,
-                               std::string("/tmp/uptime-login-successful")));
+    BootTimesLoader::RecordCurrentStats("login-successful");
     registrar_.Remove(this, NotificationType::LOGIN_AUTHENTICATION,
                       NotificationService::AllSources());
   }