Merge pull request #693 from mathjax/issue2678

Clear the stylesheet when used in a new MathDocument.  (mathjax/MathJax#2678)

Author: dpvc

ts/output/chtml.ts

@@ -140,6 +140,13 @@ CommonOutputJax<N, T, D, CHTMLWrapper<N, T, D>, CHTMLWrapperFactory<N, T, D>, CH
     this.font.adaptiveCSS(this.options.adaptiveCSS);
   }
 
+  /**
+   * @override
+   */
+  public initialize() {
+    this.chtmlStyles = null;
+  }
+
   /**
    * @override
    */

ts/output/svg.ts

@@ -135,8 +135,9 @@ CommonOutputJax<N, T, D, SVGWrapper<N, T, D>, SVGWrapperFactory<N, T, D>, SVGFon
    */
   public initialize() {
     if (this.options.fontCache === 'global') {
-      this.fontCache.clearCache();
+      this.clearFontCache();
     }
+    this.svgStyles = null;
   }
 
   /**