Have enclosingPositionedAncestor() detect whether it walked past a certain ancestor.

Have enclosingPositionedAncestor() detect whether it walked past a certain ancestor.

This is similar to what LayoutObject::container() does.

This simplifies the code in accumulateOffsetTowardsAncestor(), which previously
had to duplicate what enclosingPositionedAncestor() did.

Also cleaned up the other call site of enclosingPositionedAncestor(). No need
to call the method twice there.

No behavioral changes intended; this is just clean-up.

R=chrishtr@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197846

[chrishtr, 2015-06-25 17:32:58]

https://codereview.chromium.org/1199673003/diff/1/Source/core/paint/Deprecate...
File Source/core/paint/DeprecatedPaintLayer.h (right):

https://codereview.chromium.org/1199673003/diff/1/Source/core/paint/Deprecate...
Source/core/paint/DeprecatedPaintLayer.h:200: DeprecatedPaintLayer*
enclosingPositionedAncestor(const DeprecatedPaintLayer* ancestor = nullptr,
bool* skippedAncestor = nullptr) const;
Please explain the extra parameters' purpose and use.

[mstensho (USE GERRIT), 2015-06-25 18:04:13]

https://codereview.chromium.org/1199673003/diff/1/Source/core/paint/Deprecate...
File Source/core/paint/DeprecatedPaintLayer.h (right):

https://codereview.chromium.org/1199673003/diff/1/Source/core/paint/Deprecate...
Source/core/paint/DeprecatedPaintLayer.h:200: DeprecatedPaintLayer*
enclosingPositionedAncestor(const DeprecatedPaintLayer* ancestor = nullptr,
bool* skippedAncestor = nullptr) const;
On 2015/06/25 17:32:58, chrishtr wrote:
> Please explain the extra parameters' purpose and use.

Done.

[chrishtr, 2015-06-25 18:05:13]

The CQ bit was checked by chrishtr@chromium.org

[chrishtr, 2015-06-25 18:05:14]

lgtm

[commit-bot: I haz the power, 2015-06-25 18:05:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1199673003/20001

[commit-bot: I haz the power, 2015-06-25 19:05:12]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197846