Added new DriveNotificationObserver interface which all observers of Google Drive invalidations sho…

chrome/browser/google_apis/drive_notification_observer.h

Index: chrome/browser/google_apis/drive_notification_observer.h
diff --git a/chrome/browser/google_apis/drive_notification_observer.h b/chrome/browser/google_apis/drive_notification_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..bc9815874f9022ee2adfcd7daed7a4fe26fb7e37
--- /dev/null
+++ b/chrome/browser/google_apis/drive_notification_observer.h
@@ -0,0 +1,28 @@
+// Copyright (c) 2013 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_GOOGLE_APIS_DRIVE_NOTIFICATION_OBSERVER_H_
+#define CHROME_BROWSER_GOOGLE_APIS_DRIVE_NOTIFICATION_OBSERVER_H_
+
+#include "base/basictypes.h"

[tfarina, 2013/04/09 13:30:13]

remove this if you remove the macro below.

[calvinlo, 2013/04/10 04:05:42]

Done.

+
+namespace google_apis {
+
+// Interface for classes which need to know when to check Google Drive for
+// updates.
+class DriveNotificationObserver {
+ public:
+  DriveNotificationObserver() {}

[tfarina, 2013/04/09 13:30:13]

no constructor.

you can't instantiate this class without subclassing it.

[calvinlo, 2013/04/10 04:05:42]

Done.

+  virtual ~DriveNotificationObserver() {}

[tfarina, 2013/04/09 13:30:13]

can you make this protected?

[calvinlo, 2013/04/10 04:05:42]

Done.

+
+  // Called when an observer should check Google Drive for updates.
+  virtual void CheckForUpdates() = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DriveNotificationObserver);

[tfarina, 2013/04/09 13:30:13]

nor this.

because you have a pure abstract interface. Yeah, I know this disallow the copy
and assign the subclass, but it's subtle.

[calvinlo, 2013/04/10 04:05:42]

Done.

+};
+
+}  // namespace google_apis
+
+#endif  // CHROME_BROWSER_GOOGLE_APIS_DRIVE_NOTIFICATION_OBSERVER_H_