Add support to previews/ for Server LoFi and LitePages

components/previews/core/previews_experiments.h

 // 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.
 
 #ifndef COMPONENTS_PREVIEWS_CORE_PREVIEWS_EXPERIMENTS_H_
 #define COMPONENTS_PREVIEWS_CORE_PREVIEWS_EXPERIMENTS_H_
 
 #include <memory>
 #include <utility>
 #include <vector>
@@ skipping 46 matching lines @@
 
 // The blacklist version for offline previews.
 int OfflinePreviewsVersion();
 
 }  // namespace params
 
 enum class PreviewsType {
   NONE = 0,
   // The user is shown an offline page as a preview.
   OFFLINE = 1,
+  // The user is shown a server lite page.
+  LITE_PAGE = 2,
+  // The user is shown a server LoFi page.
+  SERVER_LOFI = 3,
   // Insert new enum values here. Keep values sequential to allow looping
   // from NONE+1 to LAST-1.
-  LAST = 2,
+  LAST = 4,
 };
 
 typedef std::vector<std::pair<PreviewsType, int>> PreviewsTypeList;
 
 // Returns true if any client-side previews experiment is active.
 bool IsIncludedInClientSidePreviewsExperimentsFieldTrial();
 
 // Sets the appropriate state for field trial and variations to imitate the
 // offline pages field trial.
 bool EnableOfflinePreviewsForTesting();
 
 }  // namespace previews
 
 #endif  // COMPONENTS_PREVIEWS_CORE_PREVIEWS_EXPERIMENTS_H_