telemetry: track usage of 'optimizeFonts'

[kyliau]

optimizeFonts is enabled by default, but the Aurora team would like
to find out how many users explicitly turn it off.

Backend PR: https://github.com/vercel/next-telemetry/pull/56

https://nextjs.org/docs/basic-features/font-optimization

Bug

• Related issues linked using fixes #number
• Integration tests added
• Errors have helpful link attached, see contributing.md

Feature

• Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
• Related issues linked using fixes #number
• Integration tests added
• Documentation added
• Telemetry added. In case of a feature if it's used or not.
• Errors have helpful link attached, see contributing.md

Documentation / Examples

• Make sure the linting passes by running yarn lint

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
buildDuration	21.6s	20.8s	-825ms
buildDurationCached	4s	4.3s	⚠️ +239ms
nodeModulesSize	336 MB	336 MB	⚠️ +444 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.501	3.535	⚠️ +0.03
/ avg req/sec	714.14	707.13	⚠️ -7.01
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.665	1.569	-0.1
/error-in-render avg req/sec	1501.91	1592.93	+91.02

Client Bundles (main, webpack, commons)

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	28.3 kB	28.3 kB	✓
webpack-HASH.js gzip	1.45 kB	1.45 kB	✓
Overall change	72.2 kB	72.2 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
_app-HASH.js gzip	1.37 kB	1.37 kB	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	327 B	327 B	✓
dynamic-HASH.js gzip	2.38 kB	2.38 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	635 B	635 B	✓
image-HASH.js gzip	4.44 kB	4.44 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	1.87 kB	1.87 kB	✓
routerDirect..HASH.js gzip	321 B	321 B	✓
script-HASH.js gzip	383 B	383 B	✓
withRouter-HASH.js gzip	318 B	318 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	13.3 kB	13.3 kB	✓

Client Build Manifests

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
_buildManifest.js gzip	460 B	460 B	✓
Overall change	460 B	460 B	✓

Rendered Page Sizes

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
index.html gzip	524 B	524 B	✓
link.html gzip	536 B	536 B	✓
withRouter.html gzip	517 B	517 B	✓
Overall change	1.58 kB	1.58 kB	✓

---

Default Build with SWC (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
buildDuration	22.6s	22.2s	-347ms
buildDurationCached	4.1s	4.2s	⚠️ +94ms
nodeModulesSize	336 MB	336 MB	⚠️ +444 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.517	3.504	-0.01
/ avg req/sec	710.87	713.41	+2.54
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.725	1.653	-0.07
/error-in-render avg req/sec	1449.26	1512.01	+62.75

Client Bundles (main, webpack, commons)

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.3 kB	42.3 kB	✓
main-HASH.js gzip	28.6 kB	28.6 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	72.5 kB	72.5 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
_app-HASH.js gzip	1.35 kB	1.35 kB	✓
_error-HASH.js gzip	180 B	180 B	✓
amp-HASH.js gzip	305 B	305 B	✓
css-HASH.js gzip	321 B	321 B	✓
dynamic-HASH.js gzip	2.38 kB	2.38 kB	✓
head-HASH.js gzip	342 B	342 B	✓
hooks-HASH.js gzip	622 B	622 B	✓
image-HASH.js gzip	4.46 kB	4.46 kB	✓
index-HASH.js gzip	256 B	256 B	✓
link-HASH.js gzip	1.91 kB	1.91 kB	✓
routerDirect..HASH.js gzip	314 B	314 B	✓
script-HASH.js gzip	375 B	375 B	✓
withRouter-HASH.js gzip	309 B	309 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	13.2 kB	13.2 kB	✓

Client Build Manifests

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
_buildManifest.js gzip	460 B	460 B	✓
Overall change	460 B	460 B	✓

Rendered Page Sizes

	vercel/next.js canary	kyliau/next.js optimize-fonts	Change
index.html gzip	524 B	524 B	✓
link.html gzip	536 B	536 B	✓
withRouter.html gzip	517 B	517 B	✓
Overall change	1.58 kB	1.58 kB	✓

Commit: 085386e