PDFs viewed inside a <webview> should navigate the same as PDFs in tabs.

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 26 matching lines @@
       return filename;
     throw e;
   }
 }
 
 /**
  * Called when navigation happens in the current tab.
  * @param {string} url The url to be opened in the current tab.
  */
 function onNavigateInCurrentTab(url) {
-  // Prefer the tabs API because it can navigate from one file:// URL to
-  // another.
-  if (chrome.tabs)

[Sam McNally, 2015/09/18 01:03:47]

Could we change this to
  if (chrome.tabs && this.browserApi_.getStreamInfo().tabId != -1)
    chrome.tabs.update(this.browserApi_.getStreamInfo().tabId, {url: url});
  else
    window.location.href = url;

This would allow file url links to work outside webviews and webview navigations
to not leak to the last-active tab. As far as I can tell, webviews can't
navigate to file urls so this should cover everything.

[wjmaclean, 2015/09/18 16:20:45]

Yes, but in this context |this| is a "Navigator" and does not have a
|browserApi_| member. I've plumbed one through, though a tad willy-nilly, as I'm
not sure what other implications this may have. Is there anything else that
needs to be done?

It does seem to solve both our cases.

I had originally attempted to look at chrome.tabs.getTabId, which didn't work
(for fairly obvious reasons), but I wasn't aware of browserApi, so thanks for
pointing it out.

-    chrome.tabs.update({url: url});
-  else
-    window.location.href = url;
+  // chrome.tabs.update should not be used here, since it blocks the ability
+  // of an app embedding a PDF viewer inside a webview to perform in-place
+  // navigations (e.g. to the current tab). In these cases chrome.tabs.update
+  // just refers the navigation to the current browser, causing the navigation
+  // to occur in a new tab in the browser window, which is unexpected.
+  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)
@@ skipping 809 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_;
   }
 };