Remove DictionaryHelper::Get(..., ExceptionState&)

No one uses it.

Bug: 775318, 624278
Change-Id: I1efddd76f8a7eba5fbe4a0bf1eb12899b391baa7
Reviewed-on: https://chromium-review.googlesource.com/722299
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509289}
2 files changed