[File Manager] Better message when trying to open unsupported files

chrome/browser/resources/file_manager/js/mock_chrome.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.
 
 function MockEventSource() {
   this.listeners_ = [];
 }
 
 /**
  * Add a listener.
@@ skipping 49 matching lines @@
    */
   requestLocalFileSystem: function(callback) {
     window.webkitRequestFileSystem(window.PERSISTENT, 16 * 1024 * 1024,
                                    callback,
                                    util.ferr('Error requesting filesystem'));
   },
 
   /**
    * View multiple files.
    */
-  viewFiles: function(selectedFiles) {
-    console.log('viewFiles called: ' + selectedFiles.length +
-                ' files selected');
-    for (var i = 0; i != selectedFiles.length; i++) {
-      window.open(selectedFiles[i]);
+  viewFiles: function(urls, actionId, callback) {
+    var success = true;
+    for (var i = 0; i != urls.length; i++) {
+      var url = urls[i];
+      if (!url.match(/\.(pdf|txt)$/i)) {
+        success = false;
+        break;
+      }
+      window.open(url);
     }
+    callback(success);
   },
 
   /**
    * Select multiple files.
    */
   selectFiles: function(selectedFiles) {
     console.log('selectFiles called: ' + selectedFiles.length +
                 ' files selected');
   },
 
@@ skipping 495 matching lines @@
       PASTE_ITEMS_REMAINING: 'Transferring $1 items',
       PASTE_CANCELLED: 'Transfer cancelled.',
       PASTE_TARGET_EXISTS_ERROR: 'Transfer failed, item exists: "$1"',
       PASTE_FILESYSTEM_ERROR: 'Transfer failed. $1',
       PASTE_UNEXPECTED_ERROR: 'Transfer failed, unexpected error: $1',
 
       CANCEL_LABEL: 'Cancel',
       OPEN_LABEL: 'Open',
       SAVE_LABEL: 'Save',
       OK_LABEL: 'OK',
-      NO_ACTION_FOR_FILE: "To view this file, convert it to a format that's viewable on the web. <a target='_blank' href='$1'>Learn More.</a>",
+      NO_ACTION_FOR_FILE: 'This file type is not supported. Please visit the ' +
+          '<a target=\'_blank\' href=\'$1\'>Chrome Web Store</a>' +
+          ' to find an app that can open this type of file.' +
+          ' <a target=\'_blank\' href=\'$2\'>Learn More.</a>',
 
       DEFAULT_NEW_FOLDER_NAME: 'New Folder',
       MORE_FILES: 'Show all files',
 
       SELECT_FOLDER_TITLE: 'Select a folder to open',
       SELECT_OPEN_FILE_TITLE: 'Select a file to open',
       SELECT_OPEN_MULTI_FILE_TITLE: 'Select one or more files',
       SELECT_SAVEAS_FILE_TITLE: 'Save file as',
 
       COMPUTING_SELECTION: 'Computing selection...',
@@ skipping 215 matching lines @@
     compare: function(a, b) {
       if (a > b) return 1;
       if (a < b) return -1;
       return 0;
     }
   };
 };
 
 return v8Intl;
 }());