Link to the flakiness dashboard:
https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=chrome_public_test_apk&tests=org.chromium.chrome.browser.metrics.MainIntentBehaviorMetricsIntegrationTest%23testLaunch_From_InAppActivities

Error log from https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Marshmallow%20Tablet%20Tester/1154:
java.lang.AssertionError: org.chromium.chrome.browser.bookmarks.BookmarkActivity did not start in: 3000
	at org.junit.Assert.fail(Assert.java:88)
	at org.junit.Assert.assertTrue(Assert.java:41)
	at org.junit.Assert.assertNotNull(Assert.java:712)
	at org.chromium.chrome.test.util.ActivityUtils.waitForActivityWithTimeout(ActivityUtils.java:160)
	at org.chromium.chrome.test.util.ActivityUtils.waitForActivity(ActivityUtils.java:118)
	at org.chromium.chrome.browser.metrics.MainIntentBehaviorMetricsIntegrationTest.testLaunch_From_InAppActivities(MainIntentBehaviorMetricsIntegrationTest.java:277)
	at java.lang.reflect.Method.invoke(Native Method)
	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)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.chromium.base.test.ScreenshotOnFailureStatement.evaluate(ScreenshotOnFailureStatement.java:37)
	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
	at org.chromium.chrome.test.ChromeActivityTestRule$1.evaluate(ChromeActivityTestRule.java:116)
	at android.support.test.internal.statement.UiThreadStatement.evaluate(UiThreadStatement.java:55)
	at android.support.test.rule.ActivityTestRule$ActivityStatement.evaluate(ActivityTestRule.java:270)
	at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(BaseJUnit4ClassRunner.java:237)
	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(BaseJUnit4ClassRunner.java:48)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.chromium.base.test.BaseJUnit4ClassRunner.run(BaseJUnit4ClassRunner.java:220)
	at org.junit.runners.Suite.runChild(Suite.java:128)
	at org.junit.runners.Suite.runChild(Suite.java:27)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
	at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:59)
	at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:262)
	at org.chromium.base.test.BaseChromiumAndroidJUnitRunner.onStart(BaseChromiumAndroidJUnitRunner.java:125)
	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1879)

Error log from https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/android-kitkat-arm-rel/9069:
java.lang.AssertionError: expected:<1> but was:<3>
	at org.junit.Assert.fail(PG:88)
	at org.junit.Assert.failNotEquals(PG:834)
	at org.junit.Assert.assertEquals(PG:645)
	at org.junit.Assert.assertEquals(PG:631)
	at org.chromium.chrome.browser.metrics.MainIntentBehaviorMetricsIntegrationTest.testLaunch_From_InAppActivities(PG:299)
	at java.lang.reflect.Method.invokeNative(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:515)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(PG:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(PG:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(PG:52)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(PG:17)
	at org.chromium.base.test.ScreenshotOnFailureStatement.evaluate(PG:37)
	at org.junit.internal.runners.statements.RunAfters.evaluate(PG:27)
	at org.chromium.chrome.test.ChromeActivityTestRule$1.evaluate(PG:116)
	at android.support.test.internal.statement.UiThreadStatement.evaluate(PG:55)
	at android.support.test.rule.ActivityTestRule$ActivityStatement.evaluate(PG:270)
	at org.junit.rules.ExternalResource$1.evaluate(PG:48)
	at org.junit.rules.RunRules.evaluate(PG:20)
	at org.junit.runners.ParentRunner.runLeaf(PG:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(PG:78)
	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(PG:237)
	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(PG:48)
	at org.junit.runners.ParentRunner$3.run(PG:290)
	at org.junit.runners.ParentRunner$1.schedule(PG:71)
	at org.junit.runners.ParentRunner.runChildren(PG:288)
	at org.junit.runners.ParentRunner.access$000(PG:58)
	at org.junit.runners.ParentRunner$2.evaluate(PG:268)
	at org.junit.runners.ParentRunner.run(PG:363)
	at org.chromium.base.test.BaseJUnit4ClassRunner.run(PG:220)
	at org.junit.runners.Suite.runChild(PG:128)
	at org.junit.runners.Suite.runChild(PG:27)
	at org.junit.runners.ParentRunner$3.run(PG:290)
	at org.junit.runners.ParentRunner$1.schedule(PG:71)
	at org.junit.runners.ParentRunner.runChildren(PG:288)
	at org.junit.runners.ParentRunner.access$000(PG:58)
	at org.junit.runners.ParentRunner$2.evaluate(PG:268)
	at org.junit.runners.ParentRunner.run(PG:363)
	at org.junit.runner.JUnitCore.run(PG:137)
	at org.junit.runner.JUnitCore.run(PG:115)
	at android.support.test.internal.runner.TestExecutor.execute(PG:59)
	at android.support.test.runner.AndroidJUnitRunner.onStart(PG:262)
	at org.chromium.base.test.BaseChromiumAndroidJUnitRunner.onStart(PG:125)
	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1701)