Remove enum ordering dependency in StyleBuilderCustom.

StyleBuilderCustom makes an assumption that the values of EListStyleType
(which is generated) is ordered in a particular way. This might lead to
subtle breakages if the generated order changes. As part of removing
all ordering dependencies, this patch uses the generated CSSValueID to
platform enum mapping instead, which makes no assumptions about the
order of the enums.

BUG=665272

Review-Url: https://codereview.chromium.org/2694333003
Cr-Commit-Position: refs/heads/master@{#453937}
1 file changed