Comment 16 for bug 415508

The uses of path_content_summary in the test suite seem to be:

1- test_commit_builder, that use it as input to record_entry_contents: we could change them to pass in the expected (generally pretty simple) value instead

2- test_path_content_summary - these probably want to be updated to get_kind_and_executable

3- as for #2 but in test_transform

I think overall this is not an inherently dangerous api, but it is also not one that we particularly want to encourage people to use because it will tend to do too much work in reading in the whole file. What is dangerous here is that there's no clear systematic distinction between when we're talking about the convenient and when about the canonical forms.