Apply the current zoom level value to each page in Presentation Mode

web/page_view.js

@@ -327,6 +327,7 @@ var PageView = function pageView(container, id, scale,
   this.scrollIntoView = function pageViewScrollIntoView(dest) {
     if (PresentationMode.active) { // Avoid breaking presentation mode.
       dest = null;
+      PDFView.setScale(PDFView.currentScaleValue, true, true);
     }
     if (!dest) {
       scrollIntoView(div);

web/viewer.js

@@ -397,8 +397,8 @@ var PDFView = {
   },
 
   get isHorizontalScrollbarEnabled() {
-    var div = document.getElementById('viewerContainer');
-    return div.scrollWidth > div.clientWidth;
+    return (PresentationMode.active ? false :
+            (this.container.scrollWidth > this.container.clientWidth));
   },
 
   initPassiveLoading: function pdfViewInitPassiveLoading() {