A few unit tests were triggering assertions because of the refactoring done in r123375. That revision added an assertion to make sure that the root layer is not empty when given to calcDrawTransforms -- there is no reason to believe this assertion is too aggressive, and its good that it triggers. Patch coming in a moment that fixes the unit tests that trigger the assertion, they now use a non-zero size for the root layer.
Created attachment 153868 [details] Patch
I supposed it would help to CC a reviewer =)
Comment on attachment 153868 [details] Patch R=me.
Comment on attachment 153868 [details] Patch Clearing flags on attachment: 153868 Committed r123398: <http://trac.webkit.org/changeset/123398>
All reviewed patches have been landed. Closing bug.