I added pylint presubmit check for Cronet here:
https://codereview.chromium.org/1945023004/

This at least seems to verify the python isn't horribly broken (e.g. functions are called with the right number of parameters), which should have avoided the need for https://codereview.chromium.org/1942283002/.
However we would probably benefit from widdling down the "disable=" list in components/cronet/pylintrc.  I fixed some of the easy pylint failures in https://codereview.chromium.org/1945023004/ but the disable= list is still large.