Blimp Settings framework on the c++ side

blimp/client/core/settings/settings_observer.h

Index: blimp/client/core/settings/settings_observer.h
diff --git a/blimp/client/core/settings/settings_observer.h b/blimp/client/core/settings/settings_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..13c0d700b860a939fcbb741e1a8e28e87df6bf91
--- /dev/null
+++ b/blimp/client/core/settings/settings_observer.h
@@ -0,0 +1,39 @@
+// Copyright 2016 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 BLIMP_CLIENT_CORE_SETTINGS_SETTINGS_OBSERVER_H_
+#define BLIMP_CLIENT_CORE_SETTINGS_SETTINGS_OBSERVER_H_
+
+#include "base/observer_list.h"
+
+namespace blimp {
+namespace client {
+
+class Settings;
+
+class SettingsObserver {
+ public:
+  virtual ~SettingsObserver();
+
+  virtual void OnBlimpModeEnabled(bool enable) {}

[David Trainor- moved to gerrit, 2016/10/01 03:26:35]

Comment on these methods (well, mainly on OnRestartRequired).

[Menglin, 2016/10/03 23:08:27]

Done.

+  virtual void OnShowNetworkStatsChanged(bool enable) {}
+  virtual void OnRecordWholeDocumentChanged(bool enable) {}
+  virtual void OnRestartRequired() {}
+
+  Settings* settings() { return settings_; }
+
+ protected:
+  explicit SettingsObserver(Settings* settings);

[David Trainor- moved to gerrit, 2016/10/01 03:26:35]

I'd get rid of the back pointer and make the owner of the observer call
AddObserver and RemoveObserver directly.  I don't think we need to have the same
level of connectedness that we have for BlimpContents and BlimpContentsObserver.

[Menglin, 2016/10/03 23:08:27]

Done.

+
+ private:
+  // The Settings being tracked by this SettingsObserver.
+  Settings* settings_;

[David Trainor- moved to gerrit, 2016/10/01 03:26:35]

Follow up on above, remove the back pointer :)

[Menglin, 2016/10/03 23:08:27]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(SettingsObserver);
+};
+
+}  // namespace client
+}  // namespace blimp
+
+#endif  // BLIMP_CLIENT_CORE_SETTINGS_SETTINGS_OBSERVER_H_