1582314 - Remove method of "cssFloat" from ServoCSSPropList.py and special-case it in CSSStyleDeclaration

Status: NEW

(Core :: DOM: CSS Object Model, enhancement, P3)

Description

[Boris Chiou [:boris]]

Our current ServoCSSPropList.py and ServoCSSPropList.h define a special method for float (i.e. cssFloat), and its method will be used to generate the webidl interface and something like IDL name lookup. It'd be better to keep using float in these lists, and handle the special conversion to/from cssFloat when we needed it. There are some reasons:

1. The conversion of CSS property to IDL attribute and the conversion of IDL attribute to CSS property don't include cssFloat. This means we shouldn't handle it inside the standard conversion.
2. Based on [CSSOM], cssFloat should be a special attribute in CSSStyleDeclaration, so we should add it into the interface and do the same thing as float, instead of only generating cssFloat. (Though we use alias to achieve this.)
3. We introduce cssOffset for Web Animation APIs for animation property, and we want to special-case cssOffset and cssFloat to avoid the attribute name collision. Per the spec steps, we special-case cssOffset and cssFloat, and then use standard conversion. This means it'd be great to not include cssFloat in the standard conversion.