Set MathJax.Hub.processSectionDelay to 0 to fix jumping behavior in MathJax 2.5+

Fixes #3006

Author: jonmmease

src/lib/svg_text_utils.js

@@ -166,10 +166,19 @@ function texToSVG(_texString, _config, _callback) {
 
     var originalRenderer,
         originalConfig,
+        originalProcessSectionDelay,
         tmpDiv;
+
     MathJax.Hub.Queue(
     function() {
         originalConfig = Lib.extendDeepAll({}, MathJax.Hub.config);
+
+        originalProcessSectionDelay = MathJax.Hub.processSectionDelay;
+        if(MathJax.Hub.processSectionDelay !== undefined) {
+            // MathJax 3.5+
+            MathJax.Hub.processSectionDelay = 0;
+        }
+
         return MathJax.Hub.Config({
             messageStyle: 'none',
             displayAlign: 'left',
@@ -212,6 +221,9 @@ function texToSVG(_texString, _config, _callback) {
         }
     },
     function() {
+        if (originalProcessSectionDelay !== undefined) {
+            MathJax.Hub.processSectionDelay = originalProcessSectionDelay;
+        }
         return MathJax.Hub.Config(originalConfig);
     });
 }