Implement InstanceID API functions.

chrome/browser/services/gcm/instance_id/instance_id_profile_service.h

 // Copyright (c) 2015 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_SERVICES_GCM_INSTANCE_ID_INSTANCE_ID_PROFILE_SERVICE_H_
 #define CHROME_BROWSER_SERVICES_GCM_INSTANCE_ID_INSTANCE_ID_PROFILE_SERVICE_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "components/keyed_service/core/keyed_service.h"
 
 class Profile;
 
 namespace instance_id {
 
 class InstanceIDDriver;
 
 // Providing Instance ID support, via InstanceIDDriver, to a profile.
 class InstanceIDProfileService : public KeyedService {
  public:
+  // Returns whether InstanceID is enabled for |profile|.
+  static bool IsInstanceIDEnabled(Profile* profile);
+
   explicit InstanceIDProfileService(Profile* profile);
   ~InstanceIDProfileService() override;
 
+  InstanceIDDriver* driver() const { return driver_.get(); }
+
  private:
   scoped_ptr<InstanceIDDriver> driver_;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceIDProfileService);
 };
 
 }  // namespace instance_id
 
 #endif  // CHROME_BROWSER_SERVICES_GCM_INSTANCE_ID_INSTANCE_ID_PROFILE_SERVICE_H_