An update on Chromium build time

[Hans Wennborg]

This is an update on the "Chrome #include Analysis and speeding up the
build" post [1] from June last year.

There was a lot of progress after that post. Big thanks to everyone
who has been contributing #include cleanups!

While there have been some regressions too, I'm happy to announce that
we're now at a record (since measurements started) low "total build
size" (the total processed file size by the compiler when building the
'chrome' target on Linux with empty gn args), as can be seen at [2].

Lately, the build time tracker [3] has been edging closer to the 35
CPU-hour line. Last time we crossed it (on our way up) was early 2020.
I like to think that we can cross that line again, in the right
direction this time.

If you'd like to help, or just need some simplistic distraction,
consider looking for unnecessary include edges at [4]. See
https://crbug.com/242216 for example CLs.

Thanks,
Hans

1. https://groups.google.com/a/chromium.org/g/chromium-dev/c/0ZME4DuE06k/m/3QNZ4O04AwAJ
2. https://commondatastorage.googleapis.com/chromium-browser-clang/chrome_includes-index.html
3. https://commondatastorage.googleapis.com/chromium-browser-clang/build-time.html
4. https://commondatastorage.googleapis.com/chromium-browser-clang/include-analysis.html#view=edges