Sorry about this. I will add some change to components/browsing_data/core/browsing_data_utils.h before starting the trybots again and hope that this will trigger all tests to be run on all platforms. 
I will also check that unit_tests, components_unittests and ios_chrome_unittests have been run.

The cl was relanded successfully. The issue was that dependencies of string changes are not detected, so tests are skipped. 

Changing some strings in http://crrev.com/2910983002 caused two reverts because there were tests that checked for these strings. The trybots skipped all unit_tests because they didn't understand the dependency between the tests and these strings.
It would be great if we could prevent this in the future.

Is it possible to declare a dependency of a build target on a .grdp file, so that e.g. everything, that depends on components/browsing_data/content would be tested if we change browsing_data_strings.grdp?

The ios-simulator is red most of the time ios_chrome_unittests needs to run and is timing out. Is that related? That's near-P0 for V8 as it blocks rolling.

E.g.
https://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator/builds/227138
https://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator/builds/227140

I don't think that is related to my CL. 
When it caused a failure, it explicitly failed a test and didn't time out:
https://build.chromium.org/p/chromium.mac/builders/ios-simulator/builds/17967

Also the affected test (ClearBrowsingDataCollectionViewControllerTest.TestCacheCounterFormattingForLessThanAllTime) ran successfully in the build that timed out for you.

Thanks, will file a separate issue.

Moved all Infra>Client>iOS bugs to Infra>Client>Chrome + OS-iOS.

Can you investigate to see if this is still relevant?

I don't believe it's relevant anymore, archiving. If anyone thinks otherwise, please reopen and explain why.

I also don't believe it's an infrastructure issue, since the request in #c3 is to update the build dependencies.