Have the RequestCoordinator generate the offline_id

chrome/browser/android/offline_pages/recent_tab_helper.cc

Index: chrome/browser/android/offline_pages/recent_tab_helper.cc
diff --git a/chrome/browser/android/offline_pages/recent_tab_helper.cc b/chrome/browser/android/offline_pages/recent_tab_helper.cc
index ac82fd680ee34baba94f8ee6dc00f03a958fe731..05d09339283bf6aac19acf47092828c267ae1795 100644
--- a/chrome/browser/android/offline_pages/recent_tab_helper.cc
+++ b/chrome/browser/android/offline_pages/recent_tab_helper.cc
@@ -167,7 +167,7 @@ void RecentTabHelper::ContinueSnapshotAfterPurge(
   }
 
   page_model_->SavePage(
-      snapshot_url_, client_id(),
+      snapshot_url_, client_id(), 0ul,
       delegate_->CreatePageArchiver(web_contents()),
       base::Bind(&RecentTabHelper::SavePageCallback,
                  weak_ptr_factory_.GetWeakPtr()));