Bug 985855 - (Part I) Ensure active targets are always ended up committed
Bug 985855 - (Part II) Count the number of touchstart events on a target
Bug 985855 - (Part III) Commit first targets when there is a second press
Merge pull request #21473 from timdream/keyboard-multitouch-update

Bug 985855 - Commit first targets when there is a second press, r=rudyl