Known failures:
- all: computed value is always "", it should compute to something...
- animation-name: <custom-ident> not mentioned in typed om spec.
- cursor: 'grab' and 'grabbing' are still webkit prefixed.
- list-style-type: Blink implements something different to the spec.
- page: computed value is always "", <custom-ident> not mentioned in
        typedom spec
- perspective: '0' seems to compute to none.
- perspective-origin: Blink doesn't support 'none' keyword
- quotes: computed value is always ""
- size: computed value is always ""
- speak: Blink implements something different to the spec.
- transform-box: Blink doesn't support 'border-box' keyword
- z-index: computed value is always 'auto' (might be something to do
           with stacking context)

Bug: 820299
Change-Id: I629dda1c4bcac92f59cae3bddf11bd375f98e5c2
Reviewed-on: https://chromium-review.googlesource.com/1003434
Commit-Queue: Darren Shen <shend@chromium.org>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550527}