Fix assertion: !visualMetricsValues.isEmpty() in blink::SVGTextLayoutEngine::layoutTextOnLineOrPath

Fix assertion: !visualMetricsValues.isEmpty() in blink::SVGTextLayoutEngine::layoutTextOnLineOrPath

Having only whitespace within a <tspan> and setting white-space to
pre-wrap causes the !visualMetricsValues.isEmpty() assert, because
the created renderer's visualMetricsValues is empty. In fact, the
renderer shouldn't even be created in this case.

So, if the text only contains whitespace, and the white-space CSS
property is set to pre-wrap, and the text is from SVG node, then
don't create a renderer.

R=kinuko@chromium.org
BUG=416833

[pmolnar.u-szeged, 2014-10-08 15:10:09]

I don't know if this fix is any good.

It fixes the assert and does'n cause any other tests to break.

[reni, 2014-10-16 13:17:14]

Adding @eseidel to CC list since he is probably familiar with this area too.

[eseidel, 2014-10-27 17:47:42]

eseidel@chromium.org changed reviewers:
+ eseidel@chromium.org, pdr@chromium.org

[eseidel, 2014-10-27 17:47:42]

The CQ bit was checked by eseidel@chromium.org

[eseidel, 2014-10-27 17:47:43]

eseidel@chromium.org changed reviewers:
+ eseidel@chromium.org, pdr@chromium.org

[eseidel, 2014-10-27 17:47:43]

The CQ bit was checked by eseidel@chromium.org

[eseidel, 2014-10-27 17:47:43]

lgtm

[eseidel, 2014-10-27 17:47:44]

lgtm

lgtm

[commit-bot: I haz the power, 2014-10-27 17:47:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/635353002/1

[commit-bot: I haz the power, 2014-10-27 20:17:54]

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

[commit-bot: I haz the power, 2014-10-27 20:17:55]

Try jobs failed on following builders:
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/33787)

[zherczeg, 2014-11-24 09:54:26]

Peter Molnar allowed me to continue this bug.

The issue with the patch was that the new condition was placed in the wrong
line, since style.preserveNewline() is also true.

[zherczeg, 2014-11-24 10:06:36]

New issue: https://codereview.chromium.org/755613002

[lgombos, 2015-03-16 18:13:42]

On 2014/11/24 10:06:36, zherczeg wrote:
> New issue: https://codereview.chromium.org/755613002

Can we abandon this CL than - to take it out form the "review queue" ?

[zherczeg, 2015-04-03 11:14:11]

> Can we abandon this CL than - to take it out form the "review queue" ?

Yes, sure.