Revert of Moving HitTest function to DeprecatedPaintLayerStackingNode.

Revert of Moving HitTest function to DeprecatedPaintLayerStackingNode. (patchset #4 id:60001 of https://codereview.chromium.org/1158673008/)

Reason for revert:
We just learned that Slimming Paint will also be modifying the Hit Testing code, and it would therefore be better to leave the code as is for now.

Original issue's description:
> Moved HitTest function to DeprecatedPaintLayerStackingNode.
> 
> This is the first step of ultimately minimizing the code in DeprecatedPaintLayer,
> so that it can be easily removed later.
> See
> https://docs.google.com/document/d/1YApHVA0hJDWeFGxHPpJ6J5JM5Wcz2h3s24KPSFp8VMg/edit?pli=1#heading=h.j2l17vvztg48.
> 
> BUG=496770
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196690

TBR=jchaffraix@chromium.org,dsinclair@chromium.org,dmazzoni@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=496770
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196788

[chadarmstrong, 2015-06-09 16:56:11]

Created Revert of Moving HitTest function to DeprecatedPaintLayerStackingNode.

[commit-bot: I haz the power, 2015-06-09 16:56:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1175623002/1

[commit-bot: I haz the power, 2015-06-09 16:56:28]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-06-09 16:56:29]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[chrishtr, 2015-06-09 18:15:34]

chrishtr@chromium.org changed reviewers:
+ chrishtr@chromium.org

[chrishtr, 2015-06-09 18:15:34]

The CQ bit was checked by chrishtr@chromium.org

[chrishtr, 2015-06-09 18:15:34]

lgtm

[commit-bot: I haz the power, 2015-06-09 18:15:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1175623002/1

[commit-bot: I haz the power, 2015-06-09 18:16:32]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196788