ash: Convert ShelfDelegate to use WmShelf* instead of Shelf*

ash/shell/shelf_delegate_impl.cc

-// Copyright 2013 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 "ash/shell/shelf_delegate_impl.h"
-
-#include "base/strings/string_util.h"
-
-namespace ash {
-namespace shell {
-
-ShelfDelegateImpl::ShelfDelegateImpl() {}
-
-ShelfDelegateImpl::~ShelfDelegateImpl() {}
-
-void ShelfDelegateImpl::OnShelfCreated(Shelf* shelf) {}
-
-void ShelfDelegateImpl::OnShelfDestroyed(Shelf* shelf) {}
-
-void ShelfDelegateImpl::OnShelfAlignmentChanged(Shelf* shelf) {}
-
-void ShelfDelegateImpl::OnShelfAutoHideBehaviorChanged(Shelf* shelf) {}
-
-void ShelfDelegateImpl::OnShelfAutoHideStateChanged(Shelf* shelf) {}
-
-void ShelfDelegateImpl::OnShelfVisibilityStateChanged(Shelf* shelf) {}
-
-ShelfID ShelfDelegateImpl::GetShelfIDForAppID(const std::string& app_id) {
-  return 0;
-}
-
-bool ShelfDelegateImpl::HasShelfIDToAppIDMapping(ShelfID id) const {
-  return false;
-}
-
-const std::string& ShelfDelegateImpl::GetAppIDForShelfID(ShelfID id) {
-  return base::EmptyString();
-}
-
-void ShelfDelegateImpl::PinAppWithID(const std::string& app_id) {}
-
-bool ShelfDelegateImpl::IsAppPinned(const std::string& app_id) {
-  return false;
-}
-
-void ShelfDelegateImpl::UnpinAppWithID(const std::string& app_id) {}
-
-}  // namespace shell
-}  // namespace ash