Add css-contain-1.vim

See also: http://www.w3.org/TR/2017/WD-css-contain-1-20170221/

Author: hail2u

after/syntax/css/css-contain-1.vim

@@ -0,0 +1,2 @@
+syn keyword cssFontProp contained contain
+syn keyword cssFontAttr contained layout paint size

after/syntax/html.vim

@@ -5,6 +5,7 @@ syn include @htmlCss syntax/css/css-break-3.vim
 syn include @htmlCss syntax/css/css-cascade-3.vim
 syn include @htmlCss syntax/css/css-cascade-4.vim
 syn include @htmlCss syntax/css/css-color-4.vim
+syn include @htmlCss syntax/css/css-contain-1.vim
 syn include @htmlCss syntax/css/css-content-3.vim
 syn include @htmlCss syntax/css/css-counter-styles-3.vim
 syn include @htmlCss syntax/css/css-device-adapt-1.vim

test/test.css

@@ -135,6 +135,12 @@
   display: luminosity;
 }
 
+.contain-1 {
+  contain: layout;
+  display: paint;
+  display: size;
+}
+
 .content-3 {
   string-set: open;
   bookmark-level: closed;

test/test.html

@@ -157,6 +157,13 @@
 }
 </style>
 <style>
+.contain-1 {
+  contain: layout;
+  display: paint;
+  display: size;
+}
+</style>
+<style>
 .content-3 {
   string-set: open;
   bookmark-level: closed;