Add the navigation redirect-chain to Sync sessions proto for offline analysis.

content/browser/frame_host/navigation_entry_impl.cc

Index: content/browser/frame_host/navigation_entry_impl.cc
diff --git a/content/browser/frame_host/navigation_entry_impl.cc b/content/browser/frame_host/navigation_entry_impl.cc
index d5d6fc2c982e8e97c60c0edde8e8a438fd2d7822..0dd826cac372e16055de7bcc83156a21299a9efc 100644
--- a/content/browser/frame_host/navigation_entry_impl.cc
+++ b/content/browser/frame_host/navigation_entry_impl.cc
@@ -289,6 +289,15 @@ int NavigationEntryImpl::GetHttpStatusCode() const {
   return http_status_code_;
 }
 
+void NavigationEntryImpl::SetRedirectChain(
+    const std::vector<GURL>& redirect_chain) {
+  redirect_chain_ = redirect_chain;
+}
+
+const std::vector<GURL>& NavigationEntryImpl::GetRedirectChain() const {
+  return redirect_chain_;
+}
+
 void NavigationEntryImpl::SetCanLoadLocalResources(bool allow) {
   can_load_local_resources_ = allow;
 }
@@ -331,7 +340,6 @@ void NavigationEntryImpl::ResetForCommit() {
   set_is_renderer_initiated(false);
   set_transferred_global_request_id(GlobalRequestID());
   set_should_replace_entry(false);
-  redirect_chain_.clear();
   set_should_clear_history_list(false);
   set_frame_tree_node_id(-1);
 }