https://build.chromium.org/p/tryserver.chromium.android/builders/linux_android_rel_ng/builds/79757
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_android_rel_ng/builds/79620
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_android_rel_ng/builds/78594
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_android_rel_ng/builds/77642

This stack happened 3 times:
C  455.463s Main  [FAIL] org.chromium.android_webview.test.AwContentsClientFullScreenTest#testOnShowAndHideCustomViewWithBackKey_video with {--webview-sandboxed-renderer}:
C  455.464s Main  java.util.concurrent.TimeoutException: waitForCallback timed out!
C  455.464s Main  	at org.chromium.content.browser.test.util.CallbackHelper.waitForCallback(CallbackHelper.java:184)
C  455.464s Main  	at org.chromium.android_webview.test.FullScreenVideoTestAwContentsClient.waitForCustomViewHidden(FullScreenVideoTestAwContentsClient.java:109)
C  455.464s Main  	at org.chromium.android_webview.test.AwContentsClientFullScreenTest.doTestOnShowAndHideCustomViewWithBackKey(AwContentsClientFullScreenTest.java:160)
C  455.464s Main  	at org.chromium.android_webview.test.AwContentsClientFullScreenTest.testOnShowAndHideCustomViewWithBackKey_video(AwContentsClientFullScreenTest.java:136)
C  455.464s Main  	at java.lang.reflect.Method.invokeNative(Native Method)
C  455.464s Main  	at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:214)
C  455.464s Main  	at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:199)
C  455.464s Main  	at android.test.ActivityInstrumentationTestCase2.runTest(ActivityInstrumentationTestCase2.java:192)
C  455.464s Main  	at org.chromium.base.test.BaseTestResult.runParameterized(BaseTestResult.java:161)
C  455.464s Main  	at org.chromium.base.test.BaseTestResult.run(BaseTestResult.java:124)
C  455.464s Main  	at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:191)
C  455.465s Main  	at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:176)
C  455.465s Main  	at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:554)
C  455.465s Main  	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1701)


This one once:
C  391.697s Main  [FAIL] org.chromium.android_webview.test.AwContentsClientFullScreenTest#testOnShowAndHideCustomViewWithCallback_video with {--webview-sandboxed-renderer}:
C  391.697s Main  java.util.concurrent.TimeoutException: waitForCallback timed out!
C  391.697s Main  	at org.chromium.content.browser.test.util.CallbackHelper.waitForCallback(CallbackHelper.java:184)
C  391.697s Main  	at org.chromium.android_webview.test.FullScreenVideoTestAwContentsClient.waitForCustomViewShown(FullScreenVideoTestAwContentsClient.java:105)
C  391.697s Main  	at org.chromium.android_webview.test.AwContentsClientFullScreenTest.doOnShowCustomViewTest(AwContentsClientFullScreenTest.java:540)
C  391.697s Main  	at org.chromium.android_webview.test.AwContentsClientFullScreenTest.doOnShowAndHideCustomViewTest(AwContentsClientFullScreenTest.java:532)
C  391.698s Main  	at org.chromium.android_webview.test.AwContentsClientFullScreenTest.doTestOnShowAndHideCustomViewWithCallback(AwContentsClientFullScreenTest.java:103)
C  391.698s Main  	at org.chromium.android_webview.test.AwContentsClientFullScreenTest.testOnShowAndHideCustomViewWithCallback_video(AwContentsClientFullScreenTest.java:93)
C  391.698s Main  	at java.lang.reflect.Method.invokeNative(Native Method)
C  391.698s Main  	at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:214)
C  391.698s Main  	at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:199)
C  391.698s Main  	at android.test.ActivityInstrumentationTestCase2.runTest(ActivityInstrumentationTestCase2.java:192)
C  391.698s Main  	at org.chromium.base.test.BaseTestResult.runParameterized(BaseTestResult.java:161)
C  391.698s Main  	at org.chromium.base.test.BaseTestResult.run(BaseTestResult.java:124)
C  391.698s Main  	at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:191)
C  391.698s Main  	at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:176)
C  391.698s Main  	at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:554)
C  391.698s Main  	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1701)