INPUT element: Do not dispatch events in detachLayoutTree().

When a color chooser is closed, we dispatches a 'change' event asynchronously.
Some tests need to be updated due to this behavior change.

BUG=658535

Review-Url: https://codereview.chromium.org/2447653002
Cr-Commit-Position: refs/heads/master@{#427286}
9 files changed