DevTools: fix css pretty-print.
The CSS pretty-printing was regressed back in the days when all formatters
were moved to a single content builder.
The content builder assumes that added tokens are "words" - and makes sure
those do not stick together. However, CSS formatter violates this contract.
This patch is a workaround which could be merged.
BUG=
614678
R=dgozman
Committed:
https://crrev.com/aec0b6fa92b2f2bece418aede111a78b043a0655
Cr-Commit-Position: refs/heads/master@{#396332}