As part of getting ready to flip the Win x64 bots over to GN, I happened to notice that the mojo tests are not yet being run under swarming (on any platform).

I attempted to fix that on windows in https://codereview.chromium.org/1818373004/ but ran out of energy, so I'm punting this over to one of the mojo folks to figure out what all needs to be fixed in the data and data_deps entries for the GN mojo targets so that things will work.

Feel free to use my CL as a starting point; you'll need at least most if not all of the changes.