Remove |use_zero_animation_type_| in TabletModeWindowState.

|use_zero_animation_type_| in TabletModeWindowState was added to
avoid animation when exiting overview on ending window drag. This
should already handled by overview itself, since overview only
animate the windows until the first maximized/fullscreen/snapped
window.

Bug: 916331
Change-Id: I8b0db04f23f246a51e5f52349ed648d4afaefabf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1531286
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Min Chen <minch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642208}
4 files changed