Frame loads blocked by directive child-src are reported as being blocked by directive frame-src in both the console message and dispatched SecurityPolicyViolation event. You can see observe these issue by opening the attached test, test.html, and looking at the test output and the console message emitted in the Web Inspector.
Created attachment 275356 [details] Test case
<rdar://problem/25478509>
Created attachment 275364 [details] Patch and Layout Tests
Committed r198951: <http://trac.webkit.org/changeset/198951>
The tests added with this change were rebaselined in <http://trac.webkit.org/changeset/198954>