Suspecting https://crrev.com/c/1386546.

Flakiness dashboard: https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=content_shell_test_apk&tests=org.chromium.content.browser.scheduler.NativePostTaskTest%23testCreateSequencedTaskRunner

I  474.340s run_tests_on_device(01e6810da265c48a)  preparing to run org.chromium.content.browser.scheduler.NativePostTaskTest#testCreateSequencedTaskRunner: {'annotations': {u'Test': {u'expected': u'class org.junit.Test$None', u'timeout': u'0'}, u'MediumTest': {}, u'RunWith': {u'value': u'class org.chromium.base.test.BaseJUnit4ClassRunner'}, u'MinAndroidSdkLevel': {u'value': u'23'}}, 'class': u'org.chromium.content.browser.scheduler.NativePostTaskTest', 'is_junit4': True, 'method': u'testCreateSequencedTaskRunner'}
I  478.016s run_tests_on_device(01e6810da265c48a)  Logcat saved to https://luci-logdog.appspot.com/v/?s=chromium%2Fandroid%2Fswarming%2Flogcats%2F4264705e9a391c11%2F%2B%2Flogcat_logcat_org.chromium.content.browser.scheduler.NativePostTaskTest.testCreateSequencedTaskRunner_20190114T091705-UTC_01e6810da265c48a
I  478.016s archive  Writing text to logdog stream, logcat_logcat_org.chromium.content.browser.scheduler.NativePostTaskTest.testCreateSequencedTaskRunner_20190114T091705-UTC_01e6810da265c48a
I  479.153s archive  ['/b/swarming/w/ir/third_party/catapult/third_party/gsutil/gsutil.py', '-q', 'stat', 'gs://chromium-result-details/179203e22f803dd99160a2304c5956ee8074a6b5'] 
I  479.154s run_tests_on_device(01e6810da265c48a)  detected failure in org.chromium.content.browser.scheduler.NativePostTaskTest#testCreateSequencedTaskRunner. raw output:
I  479.154s run_tests_on_device(01e6810da265c48a)    INSTRUMENTATION_STATUS: numtests=1
I  479.154s run_tests_on_device(01e6810da265c48a)    INSTRUMENTATION_STATUS: stream=
I  479.154s run_tests_on_device(01e6810da265c48a)    org.chromium.content.browser.scheduler.NativePostTaskTest:
I  479.154s run_tests_on_device(01e6810da265c48a)    INSTRUMENTATION_STATUS: id=AndroidJUnitRunner
I  479.154s run_tests_on_device(01e6810da265c48a)    INSTRUMENTATION_STATUS: test=testCreateSequencedTaskRunner
I  479.155s run_tests_on_device(01e6810da265c48a)    INSTRUMENTATION_STATUS: class=org.chromium.content.browser.scheduler.NativePostTaskTest
I  479.155s run_tests_on_device(01e6810da265c48a)    INSTRUMENTATION_STATUS: current=1
I  479.155s run_tests_on_device(01e6810da265c48a)    INSTRUMENTATION_STATUS_CODE: 1
I  479.155s run_tests_on_device(01e6810da265c48a)    INSTRUMENTATION_STATUS: numtests=1
I  479.155s run_tests_on_device(01e6810da265c48a)    INSTRUMENTATION_STATUS: stream=
I  479.155s run_tests_on_device(01e6810da265c48a)    Error in testCreateSequencedTaskRunner(org.chromium.content.browser.scheduler.NativePostTaskTest):
I  479.155s run_tests_on_device(01e6810da265c48a)    java.lang.AssertionError: 
I  479.155s run_tests_on_device(01e6810da265c48a)    Expected: iterable containing [<1>, <2>, <3>]
I  479.155s run_tests_on_device(01e6810da265c48a)         but: item 1: was <3>
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:20)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:8)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.chromium.content.browser.scheduler.NativePostTaskTest.testCreateSequencedTaskRunner(NativePostTaskTest.java:99)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at java.lang.reflect.Method.invoke(Native Method)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:52)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.chromium.base.test.ScreenshotOnFailureStatement.evaluate(ScreenshotOnFailureStatement.java:41)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(BaseJUnit4ClassRunner.java:237)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(BaseJUnit4ClassRunner.java:48)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.chromium.base.test.CommitSharedPreferencesTestRule$1.evaluate(CommitSharedPreferencesTestRule.java:20)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.chromium.base.test.BaseJUnit4ClassRunner.run(BaseJUnit4ClassRunner.java:220)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.Suite.runChild(Suite.java:128)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.Suite.runChild(Suite.java:27)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
I  479.155s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
I  479.156s run_tests_on_device(01e6810da265c48a)    	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
I  479.156s run_tests_on_device(01e6810da265c48a)    	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
I  479.156s run_tests_on_device(01e6810da265c48a)    	at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
I  479.156s run_tests_on_device(01e6810da265c48a)    	at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:59)
I  479.156s run_tests_on_device(01e6810da265c48a)    	at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:262)
I  479.156s run_tests_on_device(01e6810da265c48a)    	at org.chromium.base.test.BaseChromiumAndroidJUnitRunner.onStart(BaseChromiumAndroidJUnitRunner.java:128)
I  479.156s run_tests_on_device(01e6810da265c48a)    	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1879)
I  479.156s run_tests_on_device(01e6810da265c48a)    

Sami explained that other CLs have landed on top of this so I will disable the test instead of reverting the CL. I hope that this is not the root cause of other flakiness. Breaking the FIFO property of a sequenced task runner sounds pretty serious.

Pushed https://chromium-review.googlesource.com/c/chromium/src/+/1409285 into the CQ.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/25abbe7d05b917785f97badb55303ea123f1c819

commit 25abbe7d05b917785f97badb55303ea123f1c819
Author: Dominic Battre <battre@chromium.org>
Date: Mon Jan 14 14:34:58 2019

Disable flaky NativePostTaskTest tasks

See bug for details.

TBR=ksolt@chromium.org

Bug:  920678 
Change-Id: Ie84b282b1b3dc9743bb056cef8055bacffc33cd0
Reviewed-on: https://chromium-review.googlesource.com/c/1409285
Reviewed-by: Dominic Battré <battre@chromium.org>
Commit-Queue: Dominic Battré <battre@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622446}
[modify] https://crrev.com/25abbe7d05b917785f97badb55303ea123f1c819/content/public/android/javatests/src/org/chromium/content/browser/scheduler/NativePostTaskTest.java

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2a5c8e0a42bbec6b2cb6b909a2d96849f0aa21f4

commit 2a5c8e0a42bbec6b2cb6b909a2d96849f0aa21f4
Author: Karolina Soltys <ksolt@chromium.org>
Date: Wed Jan 16 15:14:14 2019

[scheduler] Fixing b/920678.

The different Java scheduler classes were using the same type of native
scheduler due to a bug in JNI bindings. This now got fixed.

Bug:  920678 
Change-Id: I5b02ae9d446f5abd550d28ae437dc1d4cdb5d888
Reviewed-on: https://chromium-review.googlesource.com/c/1412001
Commit-Queue: Karolina Soltys <ksolt@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Reviewed-by: agrieve <agrieve@chromium.org>
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623238}
[modify] https://crrev.com/2a5c8e0a42bbec6b2cb6b909a2d96849f0aa21f4/base/BUILD.gn
[modify] https://crrev.com/2a5c8e0a42bbec6b2cb6b909a2d96849f0aa21f4/base/android/java/src/org/chromium/base/task/SequencedTaskRunnerImpl.java
[modify] https://crrev.com/2a5c8e0a42bbec6b2cb6b909a2d96849f0aa21f4/base/android/java/src/org/chromium/base/task/SingleThreadTaskRunnerImpl.java
[modify] https://crrev.com/2a5c8e0a42bbec6b2cb6b909a2d96849f0aa21f4/base/android/java/src/org/chromium/base/task/TaskRunnerImpl.java
[delete] https://crrev.com/a8572138f48f5f39449d8df713db73f3c27b45af/base/android/task_scheduler/single_thread_task_runner_android.cc
[modify] https://crrev.com/2a5c8e0a42bbec6b2cb6b909a2d96849f0aa21f4/base/android/task_scheduler/task_runner_android.cc
[modify] https://crrev.com/2a5c8e0a42bbec6b2cb6b909a2d96849f0aa21f4/base/android/task_scheduler/task_runner_android.h
[modify] https://crrev.com/2a5c8e0a42bbec6b2cb6b909a2d96849f0aa21f4/content/public/android/javatests/src/org/chromium/content/browser/scheduler/NativePostTaskTest.java