Inline SVGTextLayoutAttributes::emptyValue

Inline SVGTextLayoutAttributes::emptyValue

This function just returns a simple float - inlining it allows the
compiler to generate more efficient code (and smaller - ~.5k) code
since the relatively high overhead call can be eliminated.
Take the opportunity to change the "empty value" into NaN (instead of
"max() - 1"), with corresponding semantic changes required by that.

BUG=486669
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=195555

[fs, 2015-05-19 16:32:00]

fs@opera.com changed reviewers:
+ fmalita@chromium.org, pdr@chromium.org

[fs, 2015-05-19 21:33:13]

While walking home from the office, I got the feeling that I may have done the
size-measurement backwards, so I'd need to double-check the "smaller" claim...
The generated code did look much better though (AFAICS), so still worth it even
without. (Perf-wise it seemed to be a nose tip better than placebo-improvement.)

[pdr., 2015-05-19 21:50:28]

The CQ bit was checked by pdr@chromium.org

[pdr., 2015-05-19 21:50:29]

lgtm

[commit-bot: I haz the power, 2015-05-19 21:51:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1129333004/1

[commit-bot: I haz the power, 2015-05-19 21:54:58]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=195555