Clean up ancestorScrollingLayer

Clean up ancestorScrollingLayer

This function should have walked up the containing blocks rather than
the parents. This cl fixes that and removes the useless
ancestorCompositedScrollingLayer.

Note: the layout test here was taken from abarth's patch
https://codereview.chromium.org/340913002/

BUG=None

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=176520

[Ian Vollick, 2014-06-19 05:37:47]

As I was investigating https://codereview.chromium.org/340913002/, I noticed
that ancestorScrollingLayer was busted and thought it'd be worth landing a fix
right away.

[Ian Vollick, 2014-06-19 05:44:14]

On 2014/06/19 05:37:47, Ian Vollick wrote:
> As I was investigating https://codereview.chromium.org/340913002/, I noticed
> that ancestorScrollingLayer was busted and thought it'd be worth landing a fix
> right away.

Actually, please hold off reviewing this for a moment..

[abarth-chromium, 2014-06-19 16:00:26]

lgtm

[Ian Vollick, 2014-06-19 16:02:30]

The CQ bit was checked by vollick@chromium.org

[commit-bot: I haz the power, 2014-06-19 16:03:36]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/vollick@chromium.org/344733003/50001

[commit-bot: I haz the power, 2014-06-19 16:07:09]

Change committed as 176520

[jamesr, 2014-06-19 17:47:30]

The new layout test fails on mac:

---
/b/build/slave/WebKit_Mac10_7/build/layout-test-results/compositing/overflow/scroll-parent-absolute-expected.txt
+++
/b/build/slave/WebKit_Mac10_7/build/layout-test-results/compositing/overflow/scroll-parent-absolute-actual.txt
@@ -30,12 +30,10 @@
             (GraphicsLayer
               (position 0.00 485.00)
               (bounds 485.00 15.00)
-              (drawsContent 1)
             )
             (GraphicsLayer
               (position 485.00 0.00)
               (bounds 15.00 485.00)
-              (drawsContent 1)
             )
             (GraphicsLayer
               (position 485.00 485.00)

if this is expected, could you rebaseline?  If not, could you investigate?

[Ian Vollick, 2014-06-19 19:28:42]

On 2014/06/19 17:47:30, jamesr wrote:
> The new layout test fails on mac:
> 
> ---
>
/b/build/slave/WebKit_Mac10_7/build/layout-test-results/compositing/overflow/scroll-parent-absolute-expected.txt
> +++
>
/b/build/slave/WebKit_Mac10_7/build/layout-test-results/compositing/overflow/scroll-parent-absolute-actual.txt
> @@ -30,12 +30,10 @@
>              (GraphicsLayer
>                (position 0.00 485.00)
>                (bounds 485.00 15.00)
> -              (drawsContent 1)
>              )
>              (GraphicsLayer
>                (position 485.00 0.00)
>                (bounds 15.00 485.00)
> -              (drawsContent 1)
>              )
>              (GraphicsLayer
>                (position 485.00 485.00)
> 
> if this is expected, could you rebaseline?  If not, could you investigate?

Rebaseline is in the cq. Sigh, scrollbars. Sorry for this.