Add support to previews/ for Server LoFi and LitePages

components/previews/core/previews_io_data.h

Index: components/previews/core/previews_io_data.h
diff --git a/components/previews/core/previews_io_data.h b/components/previews/core/previews_io_data.h
index f6e85331562eaf47f76ed321e31020e3682036ea..ec097bcb28d98fd7db0b54a73db14d3bff301ae1 100644
--- a/components/previews/core/previews_io_data.h
+++ b/components/previews/core/previews_io_data.h
@@ -42,9 +42,10 @@ class PreviewsIOData : public PreviewsDecider {
 
   // Stores |previews_ui_service| as |previews_ui_service_| and posts a task to
   // InitializeOnIOThread on the IO thread.
-  void Initialize(base::WeakPtr<PreviewsUIService> previews_ui_service,
-                  std::unique_ptr<PreviewsOptOutStore> previews_opt_out_store,
-                  const PreviewsIsEnabledCallback& is_enabled_callback);
+  virtual void Initialize(
+      base::WeakPtr<PreviewsUIService> previews_ui_service,
+      std::unique_ptr<PreviewsOptOutStore> previews_opt_out_store,
+      const PreviewsIsEnabledCallback& is_enabled_callback);
 
   // Adds a navigation to |url| to the black list with result |opt_out|.
   void AddPreviewNavigation(const GURL& url, bool opt_out, PreviewsType type);