[Cleanup] Files.app: Misc style fixes in Javascript code.

chrome/browser/resources/file_manager/js/file_table.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.
 
 /**
  * Namespace for utility functions.
  */
 var filelist = {};
 
 /**
@@ skipping 535 matching lines @@
   var stopEventPropagation = function(event) {
     if (!event.shiftKey)
       event.stopPropagation();
   };
   input.setAttribute('type', 'checkbox');
   input.setAttribute('tabindex', -1);
   input.classList.add('common');
   input.addEventListener('mousedown', stopEventPropagation);
   input.addEventListener('mouseup', stopEventPropagation);
 
-  var self = this;
-  input.addEventListener('click', function(event) {
-    // Revert default action and swallow the event
-    // if this is a multiple click or Shift is pressed.
-    if (event.detail > 1 || event.shiftKey) {
-      this.checked = !this.checked;
-      stopEventPropagation(event);
-    }
-  });
+  input.addEventListener(
+      'click',
+      /**
+       * @this {HTMLInputElement}
+       */
+      function(event) {
+        // Revert default action and swallow the event
+        // if this is a multiple click or Shift is pressed.
+        if (event.detail > 1 || event.shiftKey) {
+          this.checked = !this.checked;
+          stopEventPropagation(event);
+        }
+      });
 };
 
 /**
  * Decorates selection checkbox.
  * @param {HTMLInputElement} input Element to decorate.
  * @param {Entry} entry Corresponding entry.
  * @param {cr.ui.List} list Owner list.
  */
 filelist.decorateSelectionCheckbox = function(input, entry, list) {
   filelist.decorateCheckbox(input);
@@ skipping 107 matching lines @@
         break;
       }
     }
     if (url) {
       iconDiv.style.backgroundImage = 'url(' + url + ')';
     } else {
       iconDiv.style.backgroundImage = null;
     }
   }
 };