[filebrowser] Introduce View action for supported file types (e.g. pdf).

chrome/test/data/extensions/api_test/filebrowser_component/read.js

 // Copyright (c) 2012 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.
 
 // Verifies that the filesystem_handler extension returned the content of the
 // file.
 function verifyFileContent(file, originalText, receivedText, callback) {
   var error = undefined;
   if (receivedText != originalText)
     error = {message: 'Received content does not match. ' +
                       'Expected "' + originalText + '", ' +
                       'Got "' + receivedText + '".'};
   callback(error);
 };
 
 chrome.test.runTests([function tab() {
-  var expectedTasks = {'TextAction': ['filesystem:*.txt'],
+  var expectedTasks = {'AbcAction': ['filesystem:*.abc'],
                        'BaseAction': ['filesystem:*', 'filesystem:*.*']};
   var expectations = new TestExpectations(expectedTasks, verifyFileContent);
 
   var testRunner = new TestRunner(expectations);
   testRunner.runTest();
 }]);