IDL: Support [TypeChecking=Interface] correctly on indexed setters

IDL: Support [TypeChecking=Interface] correctly on indexed setters

Normally, [TypeChecking=Interface] can be set either on an interface as
a whole, affecting all its definitions (attributes and methods), or on
individual definitions. But for indexed setter definitions

  setter ElementType (unsigned long index, ElementType value);

it had to be set explicitly for the setter definition; setting it only on
the interface as a whole did not work.

This change affects the following interfaces with indexed setters:

  SVGLengthList
  SVGNumberList
  SVGPathSegList
  SVGPointList
  SVGTransformList

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=188807

[Jens Widell, 2015-01-22 10:43:41]

jl@opera.com changed reviewers:
+ haraken@chromium.org

[Jens Widell, 2015-01-22 10:43:41]

PTAL

[haraken, 2015-01-22 11:02:48]

LGTM

[Jens Widell, 2015-01-22 11:07:40]

The CQ bit was checked by jl@opera.com

[commit-bot: I haz the power, 2015-01-22 11:08:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/862403002/1

[commit-bot: I haz the power, 2015-01-22 12:03:41]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=188807