Compile ui/keyboard/ JS, part 1: remove all warnings

ui/keyboard/resources/elements/kb-keyboard.js

 // Copyright 2014 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.
 
 /**
  * The repeat delay in milliseconds before a key starts repeating. Use the
  * same rate as Chromebook.
  * (See chrome/browser/chromeos/language_preferences.cc)
  * @const
  * @type {number}
@@ skipping 728 matching lines @@
         enterUpperOnSpace = this.shouldUpperOnSpace();
         break;
       default:
         enterUpperOnSpace = false;
         break;
     }
     // Reset control keys.
     this.onNonControlKeyTyped();
   },
 
-  /*
+  /**
    * Handles key-longpress event that is sent by kb-key-base.
    * @param {CustomEvent} event The key-longpress event dispatched by
    *     kb-key-base.
    * @param {Object} detail The detail of pressed key.
    */
   keyLongpress: function(event, detail) {
     // If the gesture is long press, remove the pointermove listener.
     this.removeEventListener('pointermove', this.swipeHandler, false);
     // Keyset transtion key.
     if (this.changeKeyset(detail)) {
@@ skipping 208 matching lines @@
            keyboardLoaded();
            return true;
          }
       }
     }
     if (keysetsLoaded)
       console.error('No default keyset found for ' + this.layout);
     return false;
   }
 });