Move preferred scrollbar style preference change listening from renderer to browser, 3 of 3.

Move preferred scrollbar style preference change listening from renderer to browser, 3 of 3.

This removes the preferred style listener from Blink, now that the browser
sends the value when it changes over IPC.

BUG=306348
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=165714

[jamesr, 2014-01-23 20:24:26]

The trybots are unhappy - has a dependency not landed or hit LKGR yet?

This patch lgtm as far as I can tell, but it's probably worth having someone
more familiar with AppKit look as well.  +thakis in case he'd like to take a
look.

[Robert Sesek, 2014-01-23 20:28:10]

On 2014/01/23 20:24:26, jamesr wrote:
> The trybots are unhappy - has a dependency not landed or hit LKGR yet?

Yeah, missed LKGR by 5 revs. Was waiting for it to go again.

[Nico, 2014-01-23 20:33:37]

lgtm

[commit-bot: I haz the power, 2014-01-23 21:48:11]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rsesek@chromium.org/136333009/50001

[commit-bot: I haz the power, 2014-01-24 07:37:35]

Change committed as 165714

[esprehn, 2014-01-24 10:45:09]

This patch made the tree red:
http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Mac10.9/builds/...

[Mike West, 2014-01-24 11:55:40]

On 2014/01/24 10:45:09, esprehn wrote:
> This patch made the tree red:
>
http://build.chromium.org/p/chromium.webkit/builders/WebKit%2520Mac10.9/build...

Reverting this locally didn't fix the tests. falken@ has a different CL in mind.

[Alpha Left Google, 2014-01-24 20:21:47]

A revert of this CL has been created in
https://codereview.chromium.org/147193002/ by hclam@chromium.org.

The reason for reverting is: This seems to be causing a mac_rel failure and is
blocking blink roll.

see here:
http://build.chromium.org/p/tryserver.chromium/builders/mac_rel/builds/215993...
.