Compute and use BiDi information in SVGTextMetricsBuilder

Compute and use BiDi information in SVGTextMetricsBuilder

This extends upon https://codereview.chromium.org/104813005, by computing
(and plumbing) directionality information for SVG text elements.
The method used is similar to that used by
RenderText::computePreferredLogicalWidths although simplified somewhat.

BUG=366939
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=172799

[eae, 2014-04-28 15:37:27]

LGTM

I shame we can't reuse more of this logic.

[fs, 2014-04-28 15:55:23]

On 2014/04/28 15:37:27, eae wrote:
> LGTM
> 
> I shame we can't reuse more of this logic.

Yes, it's a pity...

[fs, 2014-04-28 16:28:59]

pdr, if you have any comments, feel free to voice them, otherwise I think this
is ready for CQ.

[pdr., 2014-04-28 19:11:27]

On 2014/04/28 16:28:59, fs wrote:
> pdr, if you have any comments, feel free to voice them, otherwise I think this
> is ready for CQ.

LGTM2, thanks for the quick fix.

[pdr., 2014-04-28 19:11:30]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2014-04-28 19:11:50]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/fs@opera.com/253823002/40001

[commit-bot: I haz the power, 2014-04-28 20:23:58]

Change committed as 172799