PDF: Allow external navigation links in PDF bookmarks

chrome/browser/resources/pdf/elements/viewer-bookmark/viewer-bookmark.js

 // Copyright 2015 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.
 
 (function() {
   /** Amount that each level of bookmarks is indented by (px). */
   var BOOKMARK_INDENT = 20;
 
   Polymer({
     is: 'viewer-bookmark',
@@ skipping 47 matching lines @@
 
     depthChanged: function() {
       this.childDepth = this.depth + 1;
       this.$.item.style.webkitPaddingStart =
           (this.depth * BOOKMARK_INDENT) + 'px';
     },
 
     onClick: function() {
       if (this.bookmark.hasOwnProperty('page'))
         this.fire('change-page', {page: this.bookmark.page});
+      else if (this.bookmark.hasOwnProperty('uri'))
+        this.fire('navigate', {uri: this.bookmark.uri, newtab: true});
     },
 
     onEnter_: function(e) {
       // Don't allow events which have propagated up from the expand button to
       // trigger a click.
       if (e.detail.keyboardEvent.target != this.$.expand)
         this.onClick();
     },
 
     onSpace_: function(e) {
       // paper-icon-button stops propagation of space events, so there's no need
       // to check the event source here.
       this.onClick();
       // Prevent default space scroll behavior.
       e.detail.keyboardEvent.preventDefault();
     },
 
     toggleChildren: function(e) {
       this.childrenShown = !this.childrenShown;
       e.stopPropagation();  // Prevent the above onClick handler from firing.
     }
   });
 })();