Change Lo-Fi bool to bitmask to support multiple Previews types

chrome/browser/loader/chrome_resource_dispatcher_host_delegate.h

Index: chrome/browser/loader/chrome_resource_dispatcher_host_delegate.h
diff --git a/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.h b/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.h
index 195453bb8e67eb05451a0858d01e13525f0eb1d6..29f46876989ea8629e2f836a67de98d7dd36e7f4 100644
--- a/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.h
+++ b/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.h
@@ -82,7 +82,8 @@ class ChromeResourceDispatcherHostDelegate
                            content::ResourceContext* resource_context,
                            content::ResourceResponse* response) override;
   void RequestComplete(net::URLRequest* url_request) override;
-  bool ShouldEnableLoFiMode(
+  int GetPreviewsState(
+      int previews_state,
       const net::URLRequest& url_request,
       content::ResourceContext* resource_context) override;
   content::NavigationData* GetNavigationData(