Prior to this commit, number input fields would to fire valueChanges twice: once for `input` events when typing and second for the `change` event when the field lost focus (both events happen at once when using the increment and decrement buttons on the number field).
Fixes#12540
BREAKING CHANGE: Number inputs no longer listen to the `change` event.
* Tests which trigger `change` events need to be updated to trigger `input` events instead.
* The `change` event was in place to support IE9, as we found that `input` events were not fired with backspace or cut actions. If you need to maintain IE9 support, you will need to add a change event listener to number inputs and call the `onChange` method of `NumberValueAccessor` manually.
* Lastly, old versions of WebDriver would synthetically trigger the `change` event on `WebElement.clear` and `WebElement.sendKeys`. If you are using an old version of WebDriver, you may need to update tests to ensure `input` events are triggered. For example, you could use `element.sendKeys(Keys.chord(Keys.CONTROL, "a"), Keys.BACK_SPACE);` in place of `element.clear()`.
PR Close#12540
PR Close#36087