Remove DisableCompositingQueryAsserts in FV::scrollbarExistenceDidChange

Remove DisableCompositingQueryAsserts in FV::scrollbarExistenceDidChange

This patch removes a compositing query assert in
FrameView::scrollbarExistenceDidChange because no compositing state is
queried through scrollbarExistenceDidChange.

No new tests.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169878

[pdr., 2014-03-24 20:20:12]

This one may actually be this simple.

[ojan, 2014-03-24 20:20:55]

lgtm

[commit-bot: I haz the power, 2014-03-24 20:21:03]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pdr@chromium.org/208313016/1

[commit-bot: I haz the power, 2014-03-24 20:23:24]

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

[commit-bot: I haz the power, 2014-03-24 20:23:24]

Try jobs failed on following builders:
  tryserver.blink on win_blink_compile_dbg

[pdr., 2014-03-24 20:26:10]

On 2014/03/24 20:23:24, I haz the power (commit-bot) wrote:
> Try jobs failed on following builders:
>   tryserver.blink on win_blink_compile_dbg

ᕙ(⇀‸↼‶)ᕗ CQ!!!

Lets try again

[pdr., 2014-03-24 20:26:13]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2014-03-24 20:26:23]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pdr@chromium.org/208313016/1

[commit-bot: I haz the power, 2014-03-24 21:50:39]

Change committed as 169878