ref(core): Streamline and test browserPerformanceTimeOrigin

[Lms24]

A conversation about browser performance.timeOrigin (cc @timfish) made me take a look at our implementation how to get the most accurate time origin. I'm fairly sure this implementation has a few flaws we should fix but for the scope of this PR I decided to add test coverage and apply some slight bundle size savings first, before tackling them.

Specifically, this PR:

• Removes a couple of bytes, by no longer storing the source of the timeOrigin. While this would be arguably valuable, we never used this information, so right now it was just wasted space. If we ever need it, we can bring it back of course)
• Adds tests for the time origin determination, reliability testing and fallback logic
• Adds TODOs for future improvements. Some of them we can tackle directly, but I want to have them in independent PRs to be able to revert them easily.

Blocked on major: We can remove an entire branch of this code, if we decide to drop Safari 14 support (opened #18707 to track)

[github-actions]

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	24.84 kB	-	-
@sentry/browser - with treeshaking flags	23.34 kB	-	-
@sentry/browser (incl. Tracing)	41.6 kB	-0.05%	-17 B 🔽
@sentry/browser (incl. Tracing, Profiling)	46.2 kB	-0.04%	-17 B 🔽
@sentry/browser (incl. Tracing, Replay)	80.17 kB	-0.02%	-16 B 🔽
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	69.91 kB	-0.03%	-20 B 🔽
@sentry/browser (incl. Tracing, Replay with Canvas)	84.86 kB	-0.02%	-16 B 🔽
@sentry/browser (incl. Tracing, Replay, Feedback)	97.11 kB	-0.03%	-20 B 🔽
@sentry/browser (incl. Feedback)	41.57 kB	-	-
@sentry/browser (incl. sendFeedback)	29.53 kB	-	-
@sentry/browser (incl. FeedbackAsync)	34.53 kB	-	-
@sentry/browser (incl. Metrics)	25.85 kB	-	-
@sentry/browser (incl. Logs)	26.07 kB	-	-
@sentry/browser (incl. Metrics & Logs)	26.82 kB	-	-
@sentry/react	26.58 kB	-	-
@sentry/react (incl. Tracing)	43.83 kB	-0.04%	-17 B 🔽
@sentry/vue	29.3 kB	-	-
@sentry/vue (incl. Tracing)	43.42 kB	-0.05%	-18 B 🔽
@sentry/svelte	24.86 kB	-	-
CDN Bundle	27.26 kB	-	-
CDN Bundle (incl. Tracing)	42.25 kB	-0.05%	-17 B 🔽
CDN Bundle (incl. Tracing, Replay)	78.96 kB	-0.03%	-18 B 🔽
CDN Bundle (incl. Tracing, Replay, Feedback)	84.43 kB	-0.02%	-15 B 🔽
CDN Bundle - uncompressed	80.02 kB	-	-
CDN Bundle (incl. Tracing) - uncompressed	125.41 kB	-0.04%	-45 B 🔽
CDN Bundle (incl. Tracing, Replay) - uncompressed	241.95 kB	-0.02%	-45 B 🔽
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	254.74 kB	-0.02%	-45 B 🔽
@sentry/nextjs (client)	46.19 kB	-0.05%	-20 B 🔽
@sentry/sveltekit (client)	41.97 kB	-0.05%	-17 B 🔽
@sentry/node-core	51.69 kB	-	-
@sentry/node	161.61 kB	+0.01%	+1 B 🔺
@sentry/node - without tracing	93.13 kB	-	-
@sentry/aws-serverless	108.64 kB	+0.01%	+1 B 🔺

View base workflow run

[github-actions]

node-overhead report 🧳

Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.

Scenario	Requests/s	% of Baseline	Prev. Requests/s	Change %
GET Baseline	11,614	-	9,110	+27%
GET With Sentry	1,951	17%	1,662	+17%
GET With Sentry (error only)	7,817	67%	5,925	+32%
POST Baseline	1,180	-	1,170	+1%
POST With Sentry	590	50%	560	+5%
POST With Sentry (error only)	1,048	89%	1,033	+1%
MYSQL Baseline	4,099	-	3,189	+29%
MYSQL With Sentry	475	12%	397	+20%
MYSQL With Sentry (error only)	3,371	82%	2,590	+30%

View base workflow run

[logaretm]

Nice!