test surrogate pairs in Html.toHtml()

This test makes certain that codepoints that would be internally
represented via surrogate pairs are emitted as single characters
via Html.toHtml(). It also exercises the input path for these
characters via Html.fromHtml(), and checks an edge case where
disembodied or out-of-order surrogate pairs are encountered.

Bug: 11338711
Change-Id: If99b7777f8e47b84899e1017c4e7e27dff8e343a
1 file changed