Example: https://build.chromium.org/p/tryserver.chromium.android/builders/linux_android_rel_ng/builds/241836

org.chromium.chrome.browser.media.ui.NotificationActionsUpdatedTest#testActionsPersistAfterSamePageNavigation (run #1):
java.lang.RuntimeException: Exception occured while waiting for runnable
	at org.chromium.base.ThreadUtils.runOnUiThreadBlocking(ThreadUtils.java:79)
	at org.chromium.chrome.browser.media.ui.NotificationActionsUpdatedTest.assertActionsMatch(NotificationActionsUpdatedTest.java:135)
	at org.chromium.chrome.browser.media.ui.NotificationActionsUpdatedTest.testActionsPersistAfterSamePageNavigation(NotificationActionsUpdatedTest.java:87)
	at java.lang.reflect.Method.invokeNative(Native Method)
	at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:214)
	at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:199)
	at android.test.ActivityInstrumentationTestCase2.runTest(ActivityInstrumentationTestCase2.java:192)
	at org.chromium.chrome.test.ChromeActivityTestCaseBase.runTest(ChromeActivityTestCaseBase.java:752)
	at org.chromium.base.test.BaseTestResult.runParameterized(BaseTestResult.java:161)
	at org.chromium.base.test.BaseTestResult.run(BaseTestResult.java:124)
	at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:191)
	at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:176)
	at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:554)
	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1701)
Caused by: java.util.concurrent.ExecutionException: junit.framework.AssertionFailedError: expected:<[0, 1]> but was:<[]>
	at java.util.concurrent.FutureTask.report(FutureTask.java:93)
	at java.util.concurrent.FutureTask.get(FutureTask.java:163)
	at org.chromium.base.ThreadUtils.runOnUiThreadBlocking(ThreadUtils.java:77)
	... 19 more
Caused by: junit.framework.AssertionFailedError: expected:<[0, 1]> but was:<[]>
	at org.chromium.chrome.browser.media.ui.NotificationActionsUpdatedTest$4.run(NotificationActionsUpdatedTest.java:143)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:422)
	at java.util.concurrent.FutureTask.run(FutureTask.java:237)
	at android.os.Handler.handleCallback(Handler.java:733)
	at android.os.Handler.dispatchMessage(Handler.java:95)
	at android.os.Looper.loop(Looper.java:136)
	at android.app.ActivityThread.main(ActivityThread.java:5001)
	at java.lang.reflect.Method.invokeNative(Native Method)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
	at dalvik.system.NativeStart.main(Native Method)


15 of the last 200 tasks on https://build.chromium.org/p/tryserver.chromium.android/builders/linux_android_rel_ng?numbuilds=200 failed due to this, so this has significant impact on the CQ.


 Bug 674304  suggests this might be related to plznavigate -- did we turn that on by default recently or something? (jam?)

Or maybe it's just due to one of zqzhang's recent changes to that file.