Add ::part(ident) to CSS parser, guarded by CSSPartPseudoElementEnabled.


Bug: 805271
Change-Id: I64db4e0293264675bed8faa1782539760afe7666
Reviewed-on: https://chromium-review.googlesource.com/891201
Commit-Queue: Fergal Daly <fergal@chromium.org>
Reviewed-by: Takayoshi Kochi <kochi@chromium.org>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541308}
7 files changed