spelling: asynchronous

Author: jsoref

lib/legacy/legacy-element-mixin.html

@@ -200,7 +200,7 @@
        * add any required element event listeners.
        * In performance critical elements, the work done here should be kept
        * to a minimum since it is done before the element is rendered. In
-       * these elements, consider adding listeners asychronously so as not to
+       * these elements, consider adding listeners asynchronously so as not to
        * block render.
        * @protected
        */
@@ -695,7 +695,7 @@
       }
 
       /**
-       * Runs a callback function asyncronously.
+       * Runs a callback function asynchronously.
        *
        * By default (if no waitTime is specified), async callbacks are run at
        * microtask timing, which will occur before paint.