I've confirmed it works fine on canary, 52.0.2719.2, before the above CL.

Taking a look but if you have logcat, can you attach it?

Everything is working for me. csharrison: is it possible you recently switched to GN locally? If so, I think that might explain it as you're probably not using the correct signing keys to get first-party access to GMSCore due to a difference from gyp.

In gyp, you need to just have signing keys checked out but in gn you need to set: 
use_signing_keys = true
in gn args.

With that set, everythign works, unset it doesn't (cause we aren't signed correctl).

Marking fixed please re-open if you've tried that and it's still not working

Yeah I'm using GN and I don't have that option set, that's probably the issue.

However, I don't see that option using gn args --list, and adding it to my args.gn file causes it to complain that it isn't used in any buildfile.

Interesting - it's only defined in the internal chrome-for-android repo but that works for me.

You need to follow this guide:
https://sites.google.com/a/google.com/clank/engineering/sdk-build/using-android-release-test-keys

Ah okay that makes sense, thank you for the link nyquist@. I've worked around this issue already so I don't think it's necessary for me to verify this by getting ganpati access, etc. This is surely why SB hasn't been working :)

Thanks all for your help in debugging.

nyquist & yfriedman -- Do you think most clank devs have these keys set correctly?  If not, they'll be testing with some features missing and would miss regressions they've caused.  Maybe we should warn in some way.

For engineers working in areas that require first part APIs they should all have this if they follow the internal guides.

It is listed already under signing the build section of the 'Get the code. Build it.' page.

If people intentionally skip parts of the guide to setup their build environment, that feels like something that should be their prerogative, since it's not necessarily required for all work on Chrome for Android.

Also; if you feel that the internal guide is not helpful, or that it was too easy to skip that step, please feel free to update it!