Revert of Use custom scrollbars for print preview on non-retina mac displays.

Revert of Use custom scrollbars for print preview on non-retina mac displays. (patchset #8 id:140001 of https://codereview.chromium.org/1036943004/)

Reason for revert:
The bug this hack is working around was fixed in   http://src.chromium.org/viewvc/blink?view=rev&rev=193593. This hack can now be reverted.

Original issue's description:
> Use custom scrollbars for print preview on non-retina mac displays.
>
> This is a hack to workaround a blink bug where overlay scrollbars aren't
> rendered correctly in print preview. This bug is being looked at but
> until then we use custom scrollbars that imitate mac scrollbars only
> in this specific case.
>
> BUG=466039
>
> Committed: https://crrev.com/6826023abd24c8aa8981f4f0fadcf98f0f962bba
> Cr-Commit-Position: refs/heads/master@{#322331}

BUG=466039
TBR=thestig@chromium.org

Committed: https://crrev.com/0c5f11acb945cf2d0b5a82634be29a62c1416f4a
Cr-Commit-Position: refs/heads/master@{#324965}

[raymes, 2015-04-13 01:48:38]

Created Revert of Use custom scrollbars for print preview on non-retina mac
displays.

[Sam McNally, 2015-04-13 01:58:06]

lgtm

[raymes, 2015-04-13 23:09:30]

TBR thestig@ for component_resources.grd

[raymes, 2015-04-13 23:09:34]

The CQ bit was checked by raymes@chromium.org

[commit-bot: I haz the power, 2015-04-13 23:11:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1085483002/1

[Lei Zhang, 2015-04-13 23:42:00]

lgtm

[commit-bot: I haz the power, 2015-04-14 00:44:56]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-14 00:46:41]

Patchset 1 (id:??) landed as
https://crrev.com/0c5f11acb945cf2d0b5a82634be29a62c1416f4a
Cr-Commit-Position: refs/heads/master@{#324965}