Previously I was multiplying the calculated height of the text by the scale factor. This fails in the case where we have a long string that doesn't fit, but it is shrunk so much that it now has more than enough room in the renderer's constrained size. In this case we fail to update the calculated size's width.
Also updated `lineCountForString` in `ASTextKitFontSizeAdjuster` to reuse a sizer layout manager and text container.
bcb1832fcd