Chrome Version: (copy from chrome://version)
OS: (e.g. Win7, OSX 10.9.5, etc...)

What steps will reproduce the problem?
(1) Check out ToT (d9499133c2f640b6e852197e6b11126ff45637ad)
(2) Move chrome/browser/ui/views/website_settings/website_settings_popup_view_unittest.cc -> chrome/browser/ui/views/page_info/website_settings_popup_view_unittest.cc (into a new folder)
(3) Run `tools/git/mass-rename.py`

What is the expected result?
`chrome/test/BUILD.gn` is updated with the new filename.

What happens instead?
It's not updated.

However, if you move a non-unit test file in that folder, the appropriate build file (chrome/browser/ui/BUILD.gn) is updated.

It's especially frustrating because moving a bunch of files + their unit tests will appear to work at first glance, because Chrome still compiles. (Building all other targets can be slow, and is usually not worth the time.) And then you upload your CL and all the bots get angry.