Fixed DOM traversal using NodeRenderingTraversal::parent().

Fixed DOM traversal using NodeRenderingTraversal::parent().

This fix was accidentally dropped from
https://codereview.chromium.org/402603005/

R=esprehn@chromium.org,rbyers@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=180654

[Rick Byers, 2014-08-18 16:12:26]

lgtm, thanks

[esprehn, 2014-08-19 18:15:49]

lgtm, would be nice to have a test too.

[mustaq, 2014-08-19 18:26:14]

The CQ bit was checked by mustaq@chromium.org

[commit-bot: I haz the power, 2014-08-19 18:27:04]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mustaq@chromium.org/486713003/20001

[mustaq, 2014-08-19 18:30:15]

The CQ bit was unchecked by mustaq@chromium.org

[commit-bot: I haz the power, 2014-08-19 18:30:17]

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

[Rick Byers, 2014-08-19 18:35:46]

On 2014/08/19 18:15:49, esprehn wrote:
> lgtm, would be nice to have a test too.

Yeah, I considered asking for that too but in this case decided against
requiring it.  The test matrix for all code paths that walk the DOM with or
without shadow DOM seems explosive.  I saw a number of other fixes to use
NodeRenderingTraversal that didn't appear to have tests for their specific use
case, so I figured expecting tests for all such cases was overkill.  Eg. if we
were going to do one massive CL where we replaced many Node::parentNode() calls
with NodeRenderingTraversal calls, would we suggest adding a new test case for
each and every call site?

Anyway, I agree it would be nice, and link highlighting should have at least one
test that verifies it works correctly in the presence of ShadowDOM.  So I'm
certainly not opposed if Mustaq wants to write one.  But I don't think we should
worry about being exhaustive in this case - applied consistently it probably
would not be practical.  WDYT?

[mustaq, 2014-08-20 14:29:51]

The CQ bit was checked by mustaq@chromium.org

[commit-bot: I haz the power, 2014-08-20 14:30:15]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mustaq@chromium.org/486713003/40001

[commit-bot: I haz the power, 2014-08-20 15:28:12]

Committed patchset #3 (40001) as 180654