Deflake and reenable top controls tests.

Deflake and reenable top controls tests.

Windows bots had trouble with the expectations in the animation loops.
Because of floating point inaccuracies, the top controls offset could be
exactly the same during the last two frames of the animation, because
the shown ratio was just off the minimum and that delta disappeared when
multiplying by the height.  This switches to checking the ratio itself,
which should match the same value that the animation system uses to
check if the next frame is needed.

BUG=456617
Committed: https://crrev.com/2c00a9a6c962300efed56e630aabbf49144c2d64
Cr-Commit-Position: refs/heads/master@{#315416}

[aelias_OOO_until_Jul13, 2015-02-09 20:53:58]

aelias@chromium.org changed reviewers:
+ dtrainor@chromium.org

[aelias_OOO_until_Jul13, 2015-02-09 20:54:05]

Hi David, PTAL.

[David Trainor- moved to gerrit, 2015-02-09 21:10:09]

lgtm

[aelias_OOO_until_Jul13, 2015-02-09 21:41:01]

New patchsets have been uploaded after l-g-t-m from dtrainor@chromium.org

[aelias_OOO_until_Jul13, 2015-02-09 22:01:05]

The CQ bit was checked by aelias@chromium.org

[commit-bot: I haz the power, 2015-02-09 22:01:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/907143002/20001

[commit-bot: I haz the power, 2015-02-09 22:42:31]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-09 22:43:23]

Patchset 2 (id:??) landed as
https://crrev.com/2c00a9a6c962300efed56e630aabbf49144c2d64
Cr-Commit-Position: refs/heads/master@{#315416}