Failure stack below.  The entire class is already marked RetryOnFailure since last year but that doesn't seem enough.

I 1491.536s run_tests_on_device(0597cb68)    java.lang.NullPointerException
I 1491.536s run_tests_on_device(0597cb68)    	at org.chromium.chrome.browser.webapps.WebappModeTest.testSetsHasBeenLaunchedOnFirstLaunch(WebappModeTest.java:279)
I 1491.537s run_tests_on_device(0597cb68)    	at java.lang.reflect.Method.invokeNative(Native Method)
I 1491.537s run_tests_on_device(0597cb68)    	at java.lang.reflect.Method.invoke(Method.java:515)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:52)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
I 1491.537s run_tests_on_device(0597cb68)    	at org.chromium.base.test.ScreenshotOnFailureStatement.evaluate(ScreenshotOnFailureStatement.java:37)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
I 1491.537s run_tests_on_device(0597cb68)    	at org.chromium.chrome.test.MultiActivityTestRule$1.evaluate(MultiActivityTestRule.java:45)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
I 1491.537s run_tests_on_device(0597cb68)    	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(BaseJUnit4ClassRunner.java:135)
I 1491.537s run_tests_on_device(0597cb68)    	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(BaseJUnit4ClassRunner.java:36)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.Suite.runChild(Suite.java:128)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.Suite.runChild(Suite.java:27)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
I 1491.537s run_tests_on_device(0597cb68)    	at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
I 1491.537s run_tests_on_device(0597cb68)    	at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:59)
I 1491.537s run_tests_on_device(0597cb68)    	at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:262)
I 1491.537s run_tests_on_device(0597cb68)    	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1701)

Reverting in https://chromium-review.googlesource.com/c/590955/

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f88d362270b217f6d61bbd6fdaa65f5195a2447f

commit f88d362270b217f6d61bbd6fdaa65f5195a2447f
Author: Alexandre Elias <aelias@chromium.org>
Date: Fri Jul 28 01:23:46 2017

Disable flaky WebappModeTest.testSetsHasBeenLaunchedOnFirstLaunch.

This test is flaking even with RetryOnFailure at the class level, so
disable it.

TBR=pkotwicz
NOTRY=true
BUG=749375

Change-Id: Ie95b535303287ee1d39d46cfe7ae1a7659dcf530
Reviewed-on: https://chromium-review.googlesource.com/590955
Commit-Queue: Alexandre Elias <aelias@chromium.org>
Reviewed-by: Alexandre Elias <aelias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#490182}
[modify] https://crrev.com/f88d362270b217f6d61bbd6fdaa65f5195a2447f/chrome/android/javatests/src/org/chromium/chrome/browser/webapps/WebappModeTest.java