Use DownloadItemModel for storing chrome/ specific UI data for DownloadItems.

chrome/browser/download/download_browsertest.cc

Index: chrome/browser/download/download_browsertest.cc
diff --git a/chrome/browser/download/download_browsertest.cc b/chrome/browser/download/download_browsertest.cc
index 0e906c218c1d4ea50c4296f332b034ad2c78e8a2..22eebc08b807c81b1f57d0d0e593496a871c0e9e 100644
--- a/chrome/browser/download/download_browsertest.cc
+++ b/chrome/browser/download/download_browsertest.cc
@@ -21,6 +21,7 @@
 #include "chrome/browser/download/chrome_download_manager_delegate.h"
 #include "chrome/browser/download/download_crx_util.h"
 #include "chrome/browser/download/download_history.h"
+#include "chrome/browser/download/download_item_model.h"
 #include "chrome/browser/download/download_prefs.h"
 #include "chrome/browser/download/download_request_limiter.h"
 #include "chrome/browser/download/download_service.h"
@@ -161,7 +162,7 @@ bool WasAutoOpened(DownloadItem* item) {
 
 // Called when a download starts. Marks the download as hidden.
 void SetHiddenDownloadCallback(DownloadItem* item, net::Error error) {
-  download_util::SetShouldShowInShelf(item, false);
+  DownloadItemModel(item).SetShouldShowInShelf(false);
 }
 
 }  // namespace