The plan is to collect logs for the whole test run and upload it later on
using https://github.com/actions/upload-artifact
Produced log size:
- 163MB (8.5MB zipped) for Chromium: `DEBUG=* npm run unit 2>log`
- 135MB (4.8MB zipped) for WebKit: `DEBUG=*,-pw:wrapped* npm run wunit 2>log`
- 29MB (4.0MB zipped) for Firefox: `DEBUG=* npm run funit 2>log`
This patch adds a basic source map support to test runner.
SourceMap support is powered by Chromium DevTools source map
implementation (thus copyright). Unlike popular `source-map` npm
module, it's sync and pretty straight-forward.
The `SourceMap.js` file has a few modifications wrt upstream
Chromium version:
- reverse mappings API is removed. There's no need to ever compute them
- the `upperBoundary` function from DevTools' platform is inlined
