update debounce example.

lib/utils/debounce.html

@@ -68,19 +68,28 @@
     }
   /**
    * Creates a debouncer if no debouncer is passed as a parameter
-   * or it cancels an active debouncer otherwise. For example, the following
-   * code can be called multiple times within a microtask and the provided
-   * function will be debounced (called once at the next microtask checkpoint):
+   * or it cancels an active debouncer otherwise. The following
+   * example shows how a debouncer can be called multiple times within a
+   * microtask and "debounced" such that the provided callback function is
+   * called once. Add this method to a custom element:
    *
-   * let job = Polymer.Debouncer.debounce(job, Polymer.Async.microTask, () => {
-   *   console.log('debounced!');
-   * });
+   * _debounceWork() {
+   *   this._debounceJob = Polymer.Debouncer.debounce(this._debounceJob,
+   *       Polymer.Async.microTask, () => {
+   *     this._doWork();
+   *   });
+   * }
+   *
+   * If the `_debounceWork` method is called multiple times within the same
+   * microtask, the `_doWork` function will be called only once at the next
+   * microtask checkpoint.
    *
    * Note: In testing it is often convenient to avoid asynchrony. To accomplish
    * this with a debouncer, you can use `Polymer.enqueueDebouncer` and
    * `Polymer.flush`. For example, extend the above example by adding
-   * `Polymer.enqueueDebouncer(job)`. Then in a test, call `Polymer.flush` to
-   * ensure the debouncer has completed.
+   * `Polymer.enqueueDebouncer(this._debounceJob)` at the end of the
+   * `_debounceWork` method. Then in a test, call `Polymer.flush` to ensure
+   * the debouncer has completed.
    *
    * @param {Polymer.Debouncer?} debouncer Debouncer object.
    * @param {!AsyncModule} asyncModule Object with Async interface