Move isEmptyValue and emptyValue to SVGCharacterData

Move isEmptyValue and emptyValue to SVGCharacterData

These two helpers have a stronger tie to SVGCharacterData (on which they
operate) than to SVGTextLayoutAttributes - where they are currently
defined.
Move them as described, and also add simple query helpers to make code
using them simpler and more readable.

BUG=607906
Committed: https://crrev.com/7f48ba3851fc5c37187da843a4ffe3b9fe9a4045
Cr-Commit-Position: refs/heads/master@{#390649}

[fs, 2016-04-29 12:58:48]

Description was changed from

==========
Move isEmptyValue and emptyValue to SVGCharacterData

BUG=
==========

to

==========
Move isEmptyValue and emptyValue to SVGCharacterData

These two helpers have a stronger tie to SVGCharacterData (on which they
operate) than to SVGTextLayoutAttributes - where they are currently
defined.
Move them as described, and also add simple query helpers to make code
using them simpler and more readable.

BUG=
==========

[fs, 2016-04-29 13:25:31]

Description was changed from

==========
Move isEmptyValue and emptyValue to SVGCharacterData

These two helpers have a stronger tie to SVGCharacterData (on which they
operate) than to SVGTextLayoutAttributes - where they are currently
defined.
Move them as described, and also add simple query helpers to make code
using them simpler and more readable.

BUG=
==========

to

==========
Move isEmptyValue and emptyValue to SVGCharacterData

These two helpers have a stronger tie to SVGCharacterData (on which they
operate) than to SVGTextLayoutAttributes - where they are currently
defined.
Move them as described, and also add simple query helpers to make code
using them simpler and more readable.

BUG=607906
==========

[fs, 2016-04-29 13:44:24]

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

[f(malita), 2016-04-29 14:49:34]

lgtm

[fs, 2016-04-29 15:02:40]

The CQ bit was checked by fs@opera.com

[commit-bot: I haz the power, 2016-04-29 15:03:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1933183002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1933183002/1

[commit-bot: I haz the power, 2016-04-29 15:07:25]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-30 17:25:51]

Patchset 1 (id:??) landed as
https://crrev.com/7f48ba3851fc5c37187da843a4ffe3b9fe9a4045
Cr-Commit-Position: refs/heads/master@{#390649}

[commit-bot: I haz the power, 2016-04-30 18:00:39]

Description was changed from

==========
Move isEmptyValue and emptyValue to SVGCharacterData

These two helpers have a stronger tie to SVGCharacterData (on which they
operate) than to SVGTextLayoutAttributes - where they are currently
defined.
Move them as described, and also add simple query helpers to make code
using them simpler and more readable.

BUG=607906
==========

to

==========
Move isEmptyValue and emptyValue to SVGCharacterData

These two helpers have a stronger tie to SVGCharacterData (on which they
operate) than to SVGTextLayoutAttributes - where they are currently
defined.
Move them as described, and also add simple query helpers to make code
using them simpler and more readable.

BUG=607906

Committed: https://crrev.com/7f48ba3851fc5c37187da843a4ffe3b9fe9a4045
Cr-Commit-Position: refs/heads/master@{#390649}
==========