Encountered this here:
https://chromium-review.googlesource.com/c/840142/1

Other failures:
https://ci.chromium.org/buildbot/tryserver.chromium.android/android_n5x_swarming_rel/330722
https://ci.chromium.org/buildbot/tryserver.chromium.android/android_n5x_swarming_rel/330679
https://ci.chromium.org/buildbot/tryserver.chromium.android/android_n5x_swarming_rel/330670
https://ci.chromium.org/buildbot/tryserver.chromium.android/android_n5x_swarming_rel/330643
https://ci.chromium.org/buildbot/tryserver.chromium.android/android_n5x_swarming_rel/330633
https://ci.chromium.org/buildbot/tryserver.chromium.android/android_n5x_swarming_rel/330622
https://ci.chromium.org/buildbot/tryserver.chromium.android/android_n5x_swarming_rel/330619

Error:
I  427.423s run_tests_on_device(01e7d057cc773ed2)    Error in testSelectActionBarPlainTextPaste(org.chromium.content.browser.ContentViewCoreSelectionTest):
I  427.423s run_tests_on_device(01e7d057cc773ed2)    java.lang.AssertionError: Values did not match. Expected: true, actual: false
I  427.423s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.Assert.fail(Assert.java:88)
I  427.423s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.Assert.assertTrue(Assert.java:41)
I  427.423s run_tests_on_device(01e7d057cc773ed2)    	at org.chromium.content.browser.test.util.CriteriaHelper.pollInstrumentationThread(CriteriaHelper.java:93)
I  427.423s run_tests_on_device(01e7d057cc773ed2)    	at org.chromium.content.browser.test.util.CriteriaHelper.pollUiThread(CriteriaHelper.java:172)
I  427.423s run_tests_on_device(01e7d057cc773ed2)    	at org.chromium.content.browser.test.util.CriteriaHelper.pollUiThread(CriteriaHelper.java:194)
I  427.423s run_tests_on_device(01e7d057cc773ed2)    	at org.chromium.content.browser.ContentViewCoreSelectionTest.waitForSelectActionBarVisible(ContentViewCoreSelectionTest.java:852)
I  427.423s run_tests_on_device(01e7d057cc773ed2)    	at org.chromium.content.browser.ContentViewCoreSelectionTest.testSelectActionBarPlainTextPaste(ContentViewCoreSelectionTest.java:673)
I  427.423s run_tests_on_device(01e7d057cc773ed2)    	at java.lang.reflect.Method.invoke(Native Method)
I  427.423s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:52)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.chromium.base.test.ScreenshotOnFailureStatement.evaluate(ScreenshotOnFailureStatement.java:37)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at android.support.test.internal.statement.UiThreadStatement.evaluate(UiThreadStatement.java:55)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at android.support.test.rule.ActivityTestRule$ActivityStatement.evaluate(ActivityTestRule.java:270)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(BaseJUnit4ClassRunner.java:184)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(BaseJUnit4ClassRunner.java:41)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.chromium.base.test.BaseJUnit4ClassRunner.run(BaseJUnit4ClassRunner.java:166)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.Suite.runChild(Suite.java:128)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.Suite.runChild(Suite.java:27)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
I  427.424s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
I  427.425s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
I  427.425s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
I  427.425s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
I  427.425s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
I  427.425s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
I  427.425s run_tests_on_device(01e7d057cc773ed2)    	at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
I  427.425s run_tests_on_device(01e7d057cc773ed2)    	at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:59)
I  427.425s run_tests_on_device(01e7d057cc773ed2)    	at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:262)
I  427.425s run_tests_on_device(01e7d057cc773ed2)    	at org.chromium.base.test.BaseChromiumAndroidJUnitRunner.onStart(BaseChromiumAndroidJUnitRunner.java:99)
I  427.425s run_tests_on_device(01e7d057cc773ed2)    	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1879)

amaralp@, since you re-enabled this test in  issue 592428 , could you please triage?