WPT import https://crrev.com/c/1298117 introduced new failures in external/wpt/css/css-transforms:

List of new failures:
external/wpt/css/css-transforms/animation/matrix-interpolation.html new failing tests: https://crrev.com/c/1298117/4/third_party/WebKit/LayoutTests/external/wpt/css/css-transforms/animation/matrix-interpolation-expected.txt

This import contains upstream changes from fb03205eb0fcfb47a2b5b2af7e829754bcd0aadd to af5891b44f31102a686ff74e93cb0e74f3dcf78c:
webdriver: add interactability test for zero-sized element: https://github.com/web-platform-tests/wpt/commit/af5891b44f31102a686ff74e93cb0e74f3dcf78c
webdriver: write in-view centre point tests: https://github.com/web-platform-tests/wpt/commit/196a102e84bd3e6a384057dfdaea5ee329522a43
Compare absolute dot-product to 1.0 when interpolating quaternions: https://github.com/web-platform-tests/wpt/commit/d8282c1cc9334eaecaa1e423cb0a440d2547f85a [affecting this directory]