[ios] Make |loadCompleteWithSuccess| use web::NavigationContext.

This makes it easier in the next step of the refactor to move
|loadCompleteWithSuccess| call to |loadErrorPageForNavigationItem|.

Bug: 903497
Change-Id: I988c17afee10b56ac9baf720c147a59624afc9f3
Reviewed-on: https://chromium-review.googlesource.com/c/1359320
Reviewed-by: Eugene But <eugenebut@chromium.org>
Commit-Queue: Danyao Wang <danyao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613554}
1 file changed