Created attachment 465092 [details] Testcase Attached a test case. This is causing the intrinsic size to change during layout, which results in: ASSERTION FAILED: !intrinsicSizeChanged || !view().frameView().layoutContext().isInRenderTreeLayout() The intrinsic size is first set to the default object size (300px x 150px). Then during layout the inline size gets set to 0px.
<rdar://problem/105989184>