Upstream LayoutTests/html/dialog/* to WPT.

Bug: 761790
Change-Id: I2ff688a24eb5faba6bdd5e6cd941c27275601f9f
Reviewed-on: https://chromium-review.googlesource.com/722403
Commit-Queue: Shanmuga Pandi <shanmuga.m@samsung.com>
Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Cr-Commit-Position: refs/heads/master@{#510745}
10 files changed