It appears that DeferredStatupHander.java (https://cs.chromium.org/chromium/src/chrome/android/java/src/org/chromium/chrome/browser/DeferredStartupHandler.java) has no tests (neither Junit nor Instrumentation). I could find nothing testing that the correct things are run by this class (although the test base classes do test that it finishes).

Impact: I was adding a new startup task (record restore histogram) to DeferredStartupHandler, and there was no obvious way of adding a test for this. In the end I wrote a new instrumentation test (still to land, I will add a link to it once it lands).