TestWebKitAPI.PasteImage.PasteTIFFImage seems flaky. In https://ews-build.webkit-uat.org/#/builders/19/builds/1323, the test Passed in run-api-tests step. However, in the immediately next retry step (re-run-api-tests), it failed.
It looks like this one just needs to wait for the image's "load" event (it currently does not).
*** This bug has been marked as a duplicate of bug 195160 ***