[ribbon] Use CSSPropertyName in ForEachProperty in TypedOM.

Currently, we are passing a String to ForEachProperty's callback, and then
parsing that String again with the cssPropertyID function in order to
obtain the CSSPropertyID that was lost in the conversion to String. This
is nonsense.

Use CSSPropertyName all the way instead, to retain the CSSPropertyID.

allow CSSPropertyName in HeapVector. It should be totally fine to allow
this for CSSPropertyName, as the same is already allowed for AtomicString.

This CL should have no behavior change.

Change-Id: I85305a0267e1dfd144a0558d671145b38da206b1
Reviewed-on: https://chromium-review.googlesource.com/c/1363174
Commit-Queue: Anders Hartvoll Ruud <andruud@chromium.org>
Reviewed-by: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614672}
8 files changed