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

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_ = [];
 }
 
 MockEventSource.prototype.addListener = function(listener) {
   this.listeners_.push(listener);
@@ skipping 304 matching lines @@
       EJECT_BUTTON: 'Eject',
       IMAGE_DIMENSIONS: 'Image Dimensions',
       VOLUME_LABEL: 'Volume Label',
       READ_ONLY: 'Read Only',
 
       PLAY_MEDIA: 'Play',
 
       MOUNT_ARCHIVE: 'Open',
       FORMAT_DEVICE: 'Format device',
 
+      OPEN_ACTION: 'Open',
+      INSTALL_CRX: 'Open',
+
       GALLERY: 'View and Edit',
       GALLERY_EDIT: 'Edit',
       GALLERY_SHARE: 'Share',
       GALLERY_AUTOFIX: 'Auto-fix',
       GALLERY_FIXED: 'Fixed',
       GALLERY_CROP: 'Crop',
       GALLERY_EXPOSURE: 'Brightness',
       GALLERY_BRIGHTNESS: 'Brightness',
       GALLERY_CONTRAST: 'Contrast',
       GALLERY_ROTATE_LEFT: 'Left',
@@ skipping 179 matching lines @@
 
   setWindowHeight: function(height) {
     this.popup_.style.height = height + 'px';
   },
 
   closeWindow: function() {
     this.popup_.parentNode.removeChild(this.popup_);
     this.popup_ = null;
   }
 };