Removed unused waitForWebView* methods to chrome_earl_grey.

After downstream switched to new API,
it is safe to remove these methods
Downstream cl:
https://chrome-internal-review.googlesource.com/c/chrome/ios_internal/+/1284395

Bug: 922813
Change-Id: Ic813d77bfc6f6ad192300ced1dee8e8b2f69f36b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1623543
Commit-Queue: Maksym Onufriienko <monufriienko@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662734}
6 files changed