Maybe with a short timeout, and then drop whichever arrives too late. Do we have the metrics in place to see what overall delay this would introduce?

We already don't show PopularSites before personal suggestions (either MostLikely or TopSites) have arrived. What can happen is that TopSites arrive first, but with less than 8 suggestions. Then when PopularSites arrive later, they'll fill up the rest. That's okay IMO, since no existing suggestions will change their place.

Maybe more problematic: We can switch from TopSites to MostLikely while the NTP is open, and completely replace the suggestions. That's an old problem though, predating PopularSites.

Rephrasing the title to reflect the generic character of the required refactoring.

This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot