Test failed here:
https://ci.chromium.org/buildbot/tryserver.chromium.android/linux_android_rel_ng/456995

against this unrelated CL:
https://chromium-review.googlesource.com/837681

Log:

java.util.concurrent.TimeoutException: waitForCallback timed out!
	at org.chromium.base.test.util.CallbackHelper.waitForCallback(CallbackHelper.java:191)
	at org.chromium.base.test.util.CallbackHelper.waitForCallback(CallbackHelper.java:227)
	at org.chromium.chrome.browser.browseractions.BrowserActionActivityTest.testItemHandlingWithInitialzation(BrowserActionActivityTest.java:257)
	at org.chromium.chrome.browser.browseractions.BrowserActionActivityTest.testOpenTabInBackgroundWithInitialization(BrowserActionActivityTest.java:230)
	at java.lang.reflect.Method.invokeNative(Method.java)
	at java.lang.reflect.Method.invoke(Method.java:515)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:52)
...

This entire test suite looks flaky. Blocking on a couple of other flakes which have been filed for a couple of months. Please investigate this ASAP.