Merge CSSPropertyNames.in and SVGCSSPropertyNames.in with CSSProperties.in

This patch is part 2 of merging the CSS .in files. Having a single .in
file for listing CSS properties makes it both easier to add new properties
and add new property flags.

BUG=396992
TBR=pfeldman

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=180034

Review URL: https://codereview.chromium.org/415613002

git-svn-id: svn://svn.chromium.org/blink/trunk@180151 bbb929c8-8fbe-4397-9dbb-9b2b20218538