PDF: Use chrome.tabs.update() to navigate, when possible.

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';
 
 /**
  * @return {number} Width of a scrollbar in pixels
  */
 function getScrollbarWidth() {
@@ skipping 17 matching lines @@
 function getFilenameFromURL(url) {
   var components = url.split(/\/|\\/);
   return components[components.length - 1];
 }
 
 /**
  * Called when navigation happens in the current tab.
  * @param {string} url The url to be opened in the current tab.
  */
 function onNavigateInCurrentTab(url) {
-  window.location.href = url;
+  // Prefer the tabs API because it can navigate from one file:// URL to
+  // another.
+  if (chrome.tabs)
+    chrome.tabs.update({url: url});
+  else
+    window.location.href = url;
 }
 
 /**
  * Called when navigation happens in the new tab.
  * @param {string} url The url to be opened in the new tab.
  */
 function onNavigateInNewTab(url) {
   // Prefer the tabs API because it guarantees we can just open a new tab.
   // window.open doesn't have this guarantee.
   if (chrome.tabs)
-    chrome.tabs.create({ url: url});
+    chrome.tabs.create({url: url});
   else
     window.open(url);
 }
 
 /**
  * Whether keydown events should currently be ignored. Events are ignored when
  * an editable element has focus, to allow for proper editing controls.
  * @param {HTMLElement} activeElement The currently selected DOM node.
  * @return {boolean} True if keydown events should be ignored.
  */
@@ skipping 757 matching lines @@
    * Each bookmark is an Object containing a:
    * - title
    * - page (optional)
    * - array of children (themselves bookmarks)
    * @type {Array} the top-level bookmarks of the PDF.
    */
   get bookmarks() {
     return this.bookmarks_;
   }
 };