PDF: Strip whitespace when determining whether a PDF's title is empty.

chrome/test/data/pdf/whitespace_title_test.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.
 
 var tests = [
   /**
-   * Test that the correct title is displayed for test-title.pdf.
+   * Test that the correct title is displayed for test-whitespace-title.pdf.
    */
   function testHasCorrectTitle() {
-    chrome.test.assertEq('PDF title test', document.title);
+    chrome.test.assertEq('test-whitespace-title.pdf', document.title);
 
     chrome.test.succeed();
   }
 ];
 
 var scriptingAPI = new PDFScriptingAPI(window, window);
 scriptingAPI.setLoadCallback(function() {
   chrome.test.runTests(tests);
 });