Improve tooltip behavior for Application menu items
- Fix text antialiasing pop-in at the end of the animation in Safari.
- Fix flickery animation replay when mousing inside a tooltip element, or rapidly switching between tooltip elements.
- To accomplish this: don't play the animation if the last tip was hidden less than 500ms ago.
- Viewed a tooltip in Safari.
- Waved cursor wildly over application items, both left-right (within an item) and up-down (between items).
Tooltips appeared stable and non-flickery in all cases.
Reviewed By: chad
Maniphest Tasks: T12174
Differential Revision: https://secure.phabricator.com/D17272