ClientManagerTest.* has been failing on Marshmallow Tablet Tester since https://codereview.chromium.org/1832063002 (https://build.chromium.org/p/chromium.android/builders/Marshmallow%20Tablet%20Tester/builds/3370).

Stack trace:
[FAIL] org.chromium.chrome.browser.customtabs.ClientManagerTest#testPredictionOutcomeNoPrediction:
java.lang.ExceptionInInitializerError
  at org.chromium.base.PathUtils.getDirectoryPath(PathUtils.java:141)
  at org.chromium.base.PathUtils.getDataDirectory(PathUtils.java:150)
  at org.chromium.base.library_loader.ModernLinker.loadLibraryImpl(ModernLinker.java:391)
  at org.chromium.base.library_loader.Linker.loadLibrary(Linker.java:570)
  at org.chromium.base.library_loader.LibraryLoader.loadLibrary(LibraryLoader.java:236)
  at org.chromium.base.library_loader.LibraryLoader.loadAlreadyLocked(LibraryLoader.java:281)
  at org.chromium.base.library_loader.LibraryLoader.ensureInitialized(LibraryLoader.java:140)
  at org.chromium.chrome.browser.customtabs.ClientManagerTest.setUp(ClientManagerTest.java:30)
  at org.chromium.base.test.BaseTestResult.run(BaseTestResult.java:129)
  at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:191)
  at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:176)
  at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:555)
  at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1879)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.os.AsyncTask.cancel(boolean)' on a null object reference
  at org.chromium.base.PathUtils.getOrComputeDirectoryPaths(PathUtils.java:69)
  at org.chromium.base.PathUtils.access$000(PathUtils.java:25)
  at org.chromium.base.PathUtils$Holder.<clinit>(PathUtils.java:55)
  ... 18 more

PathUtils.getDataDirectory() has an assert that setPrivateDataDirectorySuffix() should have been called, but asserts are no-ops at the moment, so it crashes later.

It seems that other tests that require the native library to be loaded derive from NativeLibraryTestBase to take care of this.