Looks like there were several different issues.

+cc djd, mcgreevy, tansell. ptal at layout tests failures:
https://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_rel_ng/builds/480719

+cc dpranke, phajdan.jr. ptal at check_gn_headers failures. Since it failed the same way both with and without the patch would it be possible to make the build green in the future?
https://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_rel_ng/builds/479654
https://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_rel_ng/builds/479698

+cc thakis. ptal at ninja segfault (-11):
https://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_rel_ng/builds/479763

And lastly, browser_tests failures. I don't know who owns/can explain this:
https://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_rel_ng/builds/480686

We're turning off the check_gn_headers step; there are several open bugs related to it being flaky and/or flat-out wrong.

For the browser_tests failure, every test looks to be crashing, which is kinda strange. I'd want a Chromium sheriff to look into it and/or to see if we were seeing the problems elsewhere. I'd probably do that for the layout tests failures also.

Part of the problem with this CL is that it touched a build file, which means that we disable the "without patch" compile and test steps because we're not sure if they will give us the right signal or not. We should think either about how to make that clearer, or whether we can figure out a way to retry it.

We also have a patch that has been submitted to GN that'll make analyze work with GN file changes (supposedly), which is great, but it's a large patch and it'll take a little bit for Brett and I to review and get it landed.

The linux_chromium_rel_ng flakiness appears to be fixed now