Add |pageActualOption| to the list of predefined zoom options in the |scalechange| event handler in viewer.js

This patch also rearrange the order of the references to the DOM elements of the predefined zoom values, in viewer.js, to correspond with the element order in the current viewer UI. (The previous ordering is a leftover from the previous viewer UI.)

web/viewer.js

@@ -1816,9 +1816,10 @@ window.addEventListener('updateviewarea', function () {
 
 window.addEventListener('resize', function webViewerResize(evt) {
   if (PDFViewerApplication.initialized &&
-      (document.getElementById('pageWidthOption').selected ||
+      (document.getElementById('pageAutoOption').selected ||
+       /* Note: the scale is constant for |pageActualOption|. */
        document.getElementById('pageFitOption').selected ||
-       document.getElementById('pageAutoOption').selected)) {
+       document.getElementById('pageWidthOption').selected)) {
     var selectedScale = document.getElementById('scaleSelect').value;
     PDFViewerApplication.setScale(selectedScale, false);
   }
@@ -1916,9 +1917,10 @@ window.addEventListener('scalechange', function scalechange(evt) {
   customScaleOption.selected = false;
 
   if (!PDFViewerApplication.updateScaleControls &&
-      (document.getElementById('pageWidthOption').selected ||
+      (document.getElementById('pageAutoOption').selected ||
+       document.getElementById('pageActualOption').selected ||
        document.getElementById('pageFitOption').selected ||
-       document.getElementById('pageAutoOption').selected)) {
+       document.getElementById('pageWidthOption').selected)) {
     updateViewarea();
     return;
   }