[iOS] Disable fullscreen for splash screen reloads.

Some splash screens that are designed to fit the viewport of the webview
have their content size increase by the safe area insets upon reloading.
In order to continue disabling fullscreen for these pages, this CL
updates the disabling threshold by the top and bottom safe area insets.
While this strategy disables fullscreen more aggressively, it is better
to mistakenly disable fullscreen for short pages (that are slightly
longer than the scroll view) than it is to allow the animation issues
that sometimes occur when these pages are scrolled.

Bug: 924807
Change-Id: I5070b26931fdd6103f21f475a794ecb52b9e5360
Reviewed-on: https://chromium-review.googlesource.com/c/1433141
Commit-Queue: Kurt Horimoto <kkhorimoto@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Auto-Submit: Kurt Horimoto <kkhorimoto@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#627777}(cherry picked from commit 4fe064ae2732d1f6986ebe01116da27a27878268)
Reviewed-on: https://chromium-review.googlesource.com/c/1450024
Reviewed-by: Kurt Horimoto <kkhorimoto@chromium.org>
Cr-Commit-Position: refs/branch-heads/3683@{#133}
Cr-Branched-From: e51029943e0a38dd794b73caaf6373d5496ae783-refs/heads/master@{#625896}
3 files changed