Add a notification observer for the first tab load for Chrome OS.

It simply records the uptime into the tmp directory for metrics collection

BUG=none
TEST=none
Original review: http://codereview.chromium.org/548044
Patch by sosa@chromium.org

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@36876 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 43 insertions, 0 deletions

diff --git a/chrome/browser/chromeos/browser_notification_observers.h b/chrome/browser/chromeos/browser_notification_observers.h
new file mode 100644
index 0000000..91c95b9
--- /dev/null
+++ b/chrome/browser/chromeos/browser_notification_observers.h
@@ -0,0 +1,43 @@
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_CHROMEOS_BROWSER_NOTIFICATION_OBSERVERS_H_
+#define CHROME_BROWSER_CHROMEOS_BROWSER_NOTIFICATION_OBSERVERS_H_
+
+#include "base/atomic_sequence_num.h"
+#include "base/singleton.h"
+#include "chrome/common/notification_observer.h"
+#include "chrome/common/notification_registrar.h"
+#include "chrome/common/notification_source.h"
+#include "chrome/common/notification_type.h"
+
+// Global notification observers for chrome os.
+namespace chromeos {
+
+// Notification observer to log the initial time of when the first tab
+// page is rendered for Chrome OS.
+class InitialTabNotificationObserver : public NotificationObserver {
+ public:
+  InitialTabNotificationObserver();
+  virtual ~InitialTabNotificationObserver();
+
+  static InitialTabNotificationObserver* Get() {
+    return Singleton<InitialTabNotificationObserver>::get();
+  }
+
+  // NotificationObserver implementation.
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
+
+ private:
+  NotificationRegistrar registrar_;
+  base::AtomicSequenceNumber num_tabs_;
+
+  DISALLOW_COPY_AND_ASSIGN(InitialTabNotificationObserver);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_BROWSER_NOTIFICATION_OBSERVERS_H_