perf(animation): avoid ngzone with requestAnimationFrame

[liamdebeasi]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Our raf calls did were not using the patched version of raf, so ngzone would have run during animations causing a lot of jank

What is the new behavior?

• updated animations to use a patched version of raf that prevents ngzone from being called

Does this introduce a breaking change?

• Yes
• No

Other information

[ZarelaZanabria]

export const raf = (h: any) => {
if (typeof __zone_symbol__requestAnimationFrame === 'function') {
return __zone_symbol__requestAnimationFrame(h);
}
if (typeof requestAnimationFrame === 'function') {
return requestAnimationFrame(h);
}
return setTimeout(h);
};

Que significa raf y h? No entiendo que quiere hacer la función