Use non-linear tweens for tab-loading animation

* Uses EASE_IN_OUT for the progress bar to match the throbber.
* Uses FAST_OUT_SLOW_IN for favicon per UX request.

Bug: chromium:912620
Change-Id: I3ce0a376996c016904a605aa8195cc741b8e03d1
Reviewed-on: https://chromium-review.googlesource.com/c/1373016
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Commit-Queue: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615781}
1 file changed