Revert of Adding CopresenceState

components/copresence/public/copresence_observer.h

-// Copyright 2014 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 COMPONENTS_COPRESENCE_PUBLIC_COPRESENCE_OBSERVER_H_
-#define COMPONENTS_COPRESENCE_PUBLIC_COPRESENCE_OBSERVER_H_
-
-namespace copresence {
-
-class Directive;
-struct TransmittedToken;
-struct ReceivedToken;
-
-// Implement this interface to be notified of changes
-// to the state of the copresence component.
-// TODO(ckehoe): Create a LoggingObserver based on this that replaces
-// equivalent logging elsewhere. Then we know what state is being recorded.
-class CopresenceObserver {
- public:
-  // Called when the list of active directives has changed.
-  virtual void DirectivesUpdated() = 0;
-
-  // Called when a token is transmitted.
-  virtual void TokenTransmitted(const TransmittedToken& token) = 0;
-
-  // Called when a token is received.
-  virtual void TokenReceived(const ReceivedToken& token) = 0;
-
- protected:
-  virtual ~CopresenceObserver() {}
-};
-
-}  // namespace copresence
-
-#endif  // COMPONENTS_COPRESENCE_PUBLIC_COPRESENCE_OBSERVER_H_