PDF Viewer - PageUp/Down don't move pdf by page size in FitToPage mode

chrome/browser/resources/pdf/pdf.js

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 'use strict';
 
 <include src="../../../../ui/webui/resources/js/util.js">
 <include src="open_pdf_params_parser.js">
 <include src="pdf_scripting_api.js">
 <include src="viewport.js">
@@ skipping 164 matching lines @@
     var pageUpHandler = function() {
       // Go to the previous page if we are fit-to-page.
       if (this.viewport_.fittingType == Viewport.FittingType.FIT_TO_PAGE) {
         this.viewport_.goToPage(this.viewport_.getMostVisiblePage() - 1);
         // Since we do the movement of the page.
         e.preventDefault();
       } else if (fromScriptingAPI) {
         position.y -= this.viewport.size.height;
         this.viewport.position = position;
       }
-    };
+    }.bind(this);
     var pageDownHandler = function() {
       // Go to the next page if we are fit-to-page.
       if (this.viewport_.fittingType == Viewport.FittingType.FIT_TO_PAGE) {
         this.viewport_.goToPage(this.viewport_.getMostVisiblePage() + 1);
         // Since we do the movement of the page.
         e.preventDefault();
       } else if (fromScriptingAPI) {
         position.y += this.viewport.size.height;
         this.viewport.position = position;
       }
-    };
+    }.bind(this);
 
     switch (e.keyCode) {
       case 32:  // Space key.
         if (e.shiftKey)
           pageUpHandler();
         else
           pageDownHandler();
         return;
       case 33:  // Page up key.
         pageUpHandler();
@@ skipping 361 matching lines @@
 
   /**
    * @type {Viewport} the viewport of the PDF viewer.
    */
   get viewport() {
     return this.viewport_;
   }
 };
 
 var viewer = new PDFViewer();