Remove dead code for EFillSizeType::kSizeNone

This enumeration value is only used during style resolution, and thus
there should be no need to handle it elsewhere.

This allows cleaning up the ShouldFullyInvalidateFillLayersOn*Change
helpers as well, removing the only users of

StyleImage: :UsesImageContainerSize() and in turn also
Image: :UsesContainerSize(), so removing those as well.
Change-Id: I6400ca9acf98359712891fc74e1a232a2cfbc208
Reviewed-on: https://chromium-review.googlesource.com/c/1486354
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#635137}
15 files changed