Deleting the copresence API.

components/copresence/handlers/gcm_handler.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_HANDLERS_GCM_HANDLER_H_
-#define COMPONENTS_COPRESENCE_HANDLERS_GCM_HANDLER_H_
-
-#include <string>
-
-#include "base/callback_forward.h"
-#include "base/macros.h"
-
-namespace gcm {
-class GCMDriver;
-}
-
-namespace copresence {
-
-// A class to handle GCM messages from the Copresence server. As far as the
-// rest of the system is concerned, it simply provides the registered GCM ID.
-// The implementation will call other classes to enact the message contents.
-class GCMHandler {
- public:
-  // Callback to report that registration has completed.
-  // Returns an empty ID if registration failed.
-  using RegistrationCallback = base::Callback<void(const std::string&)>;
-
-  GCMHandler() {}
-  virtual ~GCMHandler() {}
-
-  // Request the GCM ID. It may be returned now or later, via the callback.
-  virtual void GetGcmId(const RegistrationCallback& callback) = 0;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(GCMHandler);
-};
-
-}  // namespace copresence
-
-#endif  // COMPONENTS_COPRESENCE_HANDLERS_GCM_HANDLER_H_