failing tests on build125-b1 include:
blink_perf.events
dromaeo.domcoreattr
dummy_benchmark.noisy_benchmark_1
kraken
media.mse_cases
media.tough_video_cases
page_cycler_v2.intl_hi_ru

Mac air 10.11 has had a full passing run so whatever was happening with build125-b1 has been resolved
passing here
https://build.chromium.org/p/chromium.perf/builders/Mac%20Air%2010.11%20Perf/builds/795

I think we should still get into what happened here so we can prevent it from happening again.

From the log, it seems like it could be some sort of swarming infra issue? 
(INFO) 2017-05-03 20:45:42,797 browser.DumpStateUponFailure:367  2017-05-03 20:42:32.098 Google Chrome[1036:48283] NSWindow warning: adding an unknown subview: <FullSizeContentView: 0x7fa0d07844b0>. Break on NSLog to debug.
2017-05-03 20:42:32.098 Google Chrome[1036:48283] Call stack:
(
    "+callStackSymbols disabled for performance reasons"
)
2017-05-03 20:42:34.446 Google Chrome[1036:48283] Errors logged by ksadmin: KSKeyedPersistentStore store directory does not exist. [com.google.UpdateEngine.CommonErrorDomain:501 - '/Library/Google/GoogleSoftwareUpdate/TicketStore' - 'KSKeyedPersistentStore.m:372']
KSPersistentTicketStore failed to load tickets. (productID: com.google.Chrome) [com.google.UpdateEngine.CoreErrorDomain:1051 - '/Library/Google/GoogleSoftwareUpdate/TicketStore/Keystone.ticketstore'] (KSKeyedPersistentStore store directory does not exist. - '/Library/Google/GoogleSoftwareUpdate/TicketStore' [com.google.UpdateEngine.CommonErrorDomain:501])
ksadmin cannot access the ticket store:<KSUpdateError:0x100605f80
	domain="com.google.UpdateEngine.CoreErrorDomain"
	code=1051
	userInfo={
		function = "-[KSProductKeyedStore(ProtectedMethods) errorForStoreError:productID:message:timeoutMessage:]";
		date = 2017-05-04 03:42:34 +0000;
		productids = {(
			"com.google.Chrome"
		)};
		filename = "KSProductKeyedStore.m";
		line = 91;
		NSFilePath = "/Library/Google/GoogleSoftwareUpdate/TicketStore/Keystone.ticketstore";
		NSUnderlyingError = <KSError:0x10030bd00
			domain="com.google.UpdateEngine.CommonErrorDomain"
			code=501
			userInfo={
				date = 2017-05-04 03:42:34 +0000;
				line = 372;
				filename = "KSKeyedPersistentStore.m";
				function = "-[KSKeyedPersistentStore(PrivateMethods) validateStorePath]";
				NSFilePath = "/Library/Google/GoogleSoftwareUpdate/TicketStore";
				NSLocalizedDescription = "KSKeyedPersistentStore store directory does not exist.";
			}
		>;
		NSLocalizedDescription = "KSPersistentTicketStore failed to load tickets.";
	}
>

(A failed build: https://build.chromium.org/p/chromium.perf/builders/Mac%20Air%2010.11%20Perf/builds/794)

+Mac experts: is this a bug in Chrome auto update on mac?

There are two logs here. The second one comes from the registration framework. I can investigate that one, but someone needs to investigate the first one.