Convert waitForWebStateContainingElement and waitForWebStateNotContainingText to compile under EG2.

Also updated bookmark utilities to return NSError instead of BOOL.

Bug: 922813
Change-Id: Ibdad2553aa8a5e32f390fcaf910a2bf525b0912c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1625854
Commit-Queue: Maksym Onufriienko <monufriienko@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663347}
5 files changed