Introduce a layering in the invalidation component as public and impl

components/invalidation/ticl_settings_provider.cc

-// 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.
-
-#include "components/invalidation/ticl_settings_provider.h"
-
-namespace invalidation {
-
-TiclSettingsProvider::Observer::~Observer() {
-}
-
-TiclSettingsProvider::TiclSettingsProvider() {
-}
-
-TiclSettingsProvider::~TiclSettingsProvider() {
-}
-
-void TiclSettingsProvider::AddObserver(Observer* observer) {
-  observers_.AddObserver(observer);
-}
-
-void TiclSettingsProvider::RemoveObserver(Observer* observer) {
-  observers_.RemoveObserver(observer);
-}
-
-void TiclSettingsProvider::FireOnUseGCMChannelChanged() {
-  FOR_EACH_OBSERVER(Observer, observers_, OnUseGCMChannelChanged());
-}
-
-}  // namespace invalidation