[Transition Tracing] onMarkerProgress

[lunaruan]

This PR adds support for onMarkerProgress (onTransitionProgress(transitionName: string, markerName: string, startTime: number, currentTime: number, pending: Array<{name: null | string}>))

We call this callback when:
* When a child suspense boundary of the marker commits in a fallback state. Only the suspense boundaries that are triggered and commit in a fallback state when the transition first occurs (and all subsequent suspense boundaries in the initial suspense boundary's subtree) are considered a part of the transition
* A child suspense boundary of the marker resolves

When we call onMarkerProgress, we call the function with a pending array. This array contains the names of the transition's suspense boundaries that are still in a fallback state

[sizebot]

Comparing: dd2d652...7c6b39b

Critical size changes

Includes critical production bundles, as well as any change greater than 2%:

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
oss-stable/react-dom/cjs/react-dom.production.min.js	=	133.13 kB	133.13 kB	=	42.76 kB	42.76 kB
oss-experimental/react-dom/cjs/react-dom.production.min.js	=	138.41 kB	138.41 kB	=	44.34 kB	44.34 kB
facebook-www/ReactDOM-prod.classic.js	+0.49%	465.88 kB	468.15 kB	+0.29%	84.37 kB	84.61 kB
facebook-www/ReactDOM-prod.modern.js	+0.50%	451.13 kB	453.39 kB	+0.30%	82.13 kB	82.37 kB
facebook-www/ReactDOMForked-prod.classic.js	+0.49%	465.88 kB	468.15 kB	+0.29%	84.37 kB	84.61 kB

Significant size changes

Includes any change greater than 0.2%:

Expand to show

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
facebook-www/ReactART-prod.modern.js	+0.77%	292.29 kB	294.55 kB	+0.55%	51.37 kB	51.65 kB
facebook-www/ReactART-prod.classic.js	+0.75%	303.13 kB	305.39 kB	+0.52%	53.22 kB	53.50 kB
facebook-www/ReactDOM-prod.modern.js	+0.50%	451.13 kB	453.39 kB	+0.30%	82.13 kB	82.37 kB
facebook-www/ReactDOMForked-prod.modern.js	+0.50%	451.13 kB	453.39 kB	+0.30%	82.13 kB	82.38 kB
facebook-www/ReactDOM-prod.classic.js	+0.49%	465.88 kB	468.15 kB	+0.29%	84.37 kB	84.61 kB
facebook-www/ReactDOMForked-prod.classic.js	+0.49%	465.88 kB	468.15 kB	+0.29%	84.37 kB	84.61 kB
facebook-www/ReactDOM-profiling.modern.js	+0.47%	481.57 kB	483.83 kB	+0.29%	86.68 kB	86.93 kB
facebook-www/ReactDOMForked-profiling.modern.js	+0.47%	481.57 kB	483.83 kB	+0.28%	86.68 kB	86.93 kB
facebook-www/ReactDOM-profiling.classic.js	+0.46%	496.39 kB	498.66 kB	+0.27%	89.00 kB	89.25 kB
facebook-www/ReactDOMForked-profiling.classic.js	+0.46%	496.39 kB	498.66 kB	+0.27%	89.00 kB	89.25 kB
facebook-www/ReactART-dev.modern.js	+0.29%	800.77 kB	803.08 kB	+0.21%	170.19 kB	170.55 kB
facebook-www/ReactART-dev.classic.js	+0.29%	810.99 kB	813.30 kB	+0.20%	172.32 kB	172.67 kB

Generated by 🚫 dangerJS against 7c6b39b

[acdlite]

So does this mean we don't call onTransitionProgress if the marker has a name? Is that the desired behavior?

[lunaruan]

We will call onTransitionProgress but not onMarkerProgress. This works because a marker is either a TracingMarker or a transition on the root. If it's a tracing marker we add a name, but if it's a transition on the root we don't. This way we can tell which is a tracing marker and which is a transition and add the right callback accordingly.