Other recipe modules often have to deal with instances of these classes, and isinstance() is not always appropriate, as they may not have access to the classes inside chromium_tests. It would be ideal if the objects themselves could expose some details about whether they are a gtest, they run on swarming, use isolate, use a script, etc.

The particular use case is code coverage. We want to make sure we measure the coverage that a given test targets contributes, and the logic to do this may depend on the type of tests.