Add css-timing-1.vim

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

Author: hail2u

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

@@ -0,0 +1 @@
+syn region cssFunction contained matchgroup=cssFunctionName start="\<frames\s*(" end=")" oneline keepend

after/syntax/html.vim

@@ -38,6 +38,7 @@ syn include @htmlCss syntax/css/css-syntax-3.vim
 syn include @htmlCss syntax/css/css-text-3.vim
 syn include @htmlCss syntax/css/css-text-4.vim
 syn include @htmlCss syntax/css/css-text-decor-3.vim
+syn include @htmlCss syntax/css/css-timing-1.vim
 syn include @htmlCss syntax/css/css-transforms-1.vim
 syn include @htmlCss syntax/css/css-typed-om-1.vim
 syn include @htmlCss syntax/css/css-ui-3.vim

test/test.css

@@ -672,6 +672,10 @@
   display: over;
 }
 
+.timing-1 {
+  display: frames(2);
+}
+
 .transforms-1 {
   backface-visibility: flat;
   perspective: preserve-3d;

test/test.html

@@ -741,6 +741,11 @@
 }
 </style>
 <style>
+.timing-1 {
+  display: frames(2);
+}
+</style>
+<style>
 .transforms-1 {
   backface-visibility: flat;
   perspective: preserve-3d;