Merge pull request #722 from mathjax/webkit-fix

Work around WebKit bug with CHTML characters.  (mathjax/MathJax#2435)

Author: dpvc

ts/output/chtml/Wrappers/TextNode.ts

@@ -58,6 +58,13 @@ CommonTextNodeMixin<CHTMLConstructor<any, any, any>>(CHTMLWrapper) {
     'mjx-utext': {
       display: 'inline-block',
       padding: '.75em 0 .2em 0'
+    },
+    //
+    //  WebKit-specific CSS to handle bug with clipped characters.
+    //  (test found at https://browserstrangeness.bitbucket.io/css_hacks.html#safari)
+    //
+    '_::-webkit-full-page-media, _:future, :root mjx-container': {
+      'will-change': 'opacity'
     }
   };