Revert of Adding split view divider widget.

Revert of Adding split view divider widget. (patchset #15 id:280001 of https://codereview.chromium.org/545393002/)

Reason for revert:
DragHandleTest.ScrollTest is failing on the bots: http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%283%29/builds/36880

Original issue's description:
> Adding split view divider widget.
>
> Adding split view divider widget which could be dragged to exit the split view.
>
> BUG=403207, 408691
>
> Committed: https://crrev.com/b47c16517f0882cbabf8c9aa9ce66711f026fd5b
> Cr-Commit-Position: refs/heads/master@{#296351}

TBR=mukai@chromium.org,oshima@chromium.org,sadrul@chromium.org,tdanderson@chromium.org,pkotwicz@chromium.org,mfomitchev@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=403207, 408691
Committed: https://crrev.com/f1546bfaabc3492485219dfb51a270bae8da41b9
Cr-Commit-Position: refs/heads/master@{#296433}

[Nico, 2014-09-24 16:19:48]

Created Revert of Adding split view divider widget.

[commit-bot: I haz the power, 2014-09-24 16:20:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/602603003/1

[commit-bot: I haz the power, 2014-09-24 16:21:21]

Committed patchset #1 (id:1) as 4c6c097400bca8fa7018e3431560e478d16ea1eb

[commit-bot: I haz the power, 2014-09-24 16:22:05]

Patchset 1 (id:??) landed as
https://crrev.com/f1546bfaabc3492485219dfb51a270bae8da41b9
Cr-Commit-Position: refs/heads/master@{#296433}