Support downloading files compatible with debugger.skia.org from devtools

[jacob314]

There is an existing _flutter.screenshotSkp service extension that exposes this data.
https://github.com/flutter/flutter/blob/master/packages/flutter_tools/lib/src/commands/screenshot.dart#L126

This functionality is already exposed on the command line as:
flutter screenshot --type=skia observatory-uri=...

https://debugger.skia.org/
can then be used to debug the data.

It isn't clear which pages in Dart DevTools the button should be included in. Perhaps the functionality is useful when debugging certain UI issues or perhaps it is useful to get more context on what Skia is doing when debugging memory or performance issues.

[jacob314]

Fyi @terrylucas, @devoncarew, @kenzieschmoll

[jacob314]

Discussing with VM developers, this information is unlikely to be very actionable for end users. To make it work well we would at minimum need to be able to trigger screenshots for slow frames. The belief is this information is likely more actionable for performance than memory.

[kenzieschmoll]

This issue is a stale feature request from 2020. As noted in the comments, exposure of SKP files was deemed unlikely to be actionable for most users and has not been prioritized. If there is more work to do here, please let us know by filing a new issue with up to date information. Thanks!