GitLab

Since we no longer create a fullscreen widget we can remove its
knowledge from WebContents and its delegate.

BUG=1134674

Change-Id: Id12cf67c5ec76dcaddb564301bf032eac4b3370d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2487148Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819183}