[SVG2] Add getters and setters to SVG*List interfaces.

[SVG2] Add getters and setters to SVG*List interfaces.

Implement the 'length' attribute and make 'numberOfItems' an alias
of that.

Spec:
https://svgwg.org/svg2-draft/types.html#InterfaceSVGStringList
https://svgwg.org/svg2-draft/types.html#InterfaceSVGNumberList
https://svgwg.org/svg2-draft/types.html#InterfaceSVGLengthList
https://svgwg.org/svg2-draft/coords.html#InterfaceSVGTransformList
https://svgwg.org/svg2-draft/coords.html#InterfaceSVGPointList

BUG=336748
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169332

[kouhei (in TOK), 2014-03-12 00:50:23]

Looks great! Would you add layout test for this?

[Erik Dahlström (inactive), 2014-03-12 07:53:18]

On 2014/03/12 00:50:23, kouhei wrote:
> Looks great! Would you add layout test for this?

Yes, will do. Feel free to review the code in the mean time.

Sidenote: while testing I found that object equality (list.getItem(0) ===
list.getItem(0) is false, and same with == too) is different compared to Firefox
and Presto, but hopefully it should be fine anyway.

[Erik Dahlström (inactive), 2014-03-14 10:00:02]

I should note that Firefox passes the test except for the setter part, which
apparently doesn't replace the values correctly in the list.

Blink doesn't expose the IDL attributes (.length and .numberOfItems) on the
SVG*List prototypes, but rather as a property on the objects themselves (same as
Presto, but different from Firefox). That's a different and unrelated issue, but
it is the reason for having the svglist-expected.txt file.

While this CL exposes "new" SVG2 functionality, this has actually been
implemented for some time in other (shipping) browsers (Opera Presto, Firefox).

[fs, 2014-03-14 16:10:07]

Non-owner LGTM.

[pdr., 2014-03-14 17:15:22]

On 2014/03/14 16:10:07, fs wrote:
> Non-owner LGTM.

LGTM2

[pdr., 2014-03-14 17:18:38]

https://codereview.chromium.org/195313003/diff/80001/Source/core/svg/properti...
File Source/core/svg/properties/NewSVGListPropertyHelper.h (right):

https://codereview.chromium.org/195313003/diff/80001/Source/core/svg/properti...
Source/core/svg/properties/NewSVGListPropertyHelper.h:174: size_t slength =
length();
size?

[Erik Dahlström (inactive), 2014-03-17 08:06:46]

The CQ bit was checked by ed@opera.com

[commit-bot: I haz the power, 2014-03-17 08:06:49]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ed@opera.com/195313003/100001

[commit-bot: I haz the power, 2014-03-17 08:40:49]

Change committed as 169332