ntp_tiles: Cleanup enum names

components/ntp_tiles/ntp_tile.cc

 // Copyright 2016 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/ntp_tiles/ntp_tile.h"
 
 namespace ntp_tiles {
 
-NTPTile::NTPTile() : source(NTPTileSource::TOP_SITES) {}
+NTPTile::NTPTile() : source(TileSource::TOP_SITES) {}
 
 NTPTile::NTPTile(const NTPTile&) = default;
 
 NTPTile::~NTPTile() {}
 
 bool operator==(const NTPTile& a, const NTPTile& b) {
   return (a.title == b.title) && (a.url == b.url) && (a.source == b.source) &&
          (a.whitelist_icon_path == b.whitelist_icon_path) &&
          (a.thumbnail_url == b.thumbnail_url) &&
          (a.favicon_url == b.favicon_url);
 }
 
 bool operator!=(const NTPTile& a, const NTPTile& b) {
   return !(a == b);
 }
 
 }  // namespace ntp_tiles