Add test coverage for interpolations using CSS wide keywords and neutral keyframes

LayoutTests/animations/interpolation/background-size-interpolation-expected.txt

Index: LayoutTests/animations/interpolation/background-size-interpolation-expected.txt
diff --git a/LayoutTests/animations/interpolation/background-size-interpolation-expected.txt b/LayoutTests/animations/interpolation/background-size-interpolation-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..4b1cf2b96b6a0e7dfc21bd56ec49bc42294f59df
--- /dev/null
+++ b/LayoutTests/animations/interpolation/background-size-interpolation-expected.txt
@@ -0,0 +1,186 @@
+This is a testharness.js-based test.
+PASS This test uses interpolation-test.js. 
+PASS CSS Transitions: property <background-size> from [] to [20px 20px, 0px 0px] at (-0.25) is [7.5px 7.5px, 12.5px 12.5px, 7.5px 7.5px, 12.5px 12.5px] 
+PASS CSS Transitions: property <background-size> from [] to [20px 20px, 0px 0px] at (0) is [10px 10px, 10px 10px, 10px 10px, 10px 10px] 
+PASS CSS Transitions: property <background-size> from [] to [20px 20px, 0px 0px] at (0.25) is [12.5px 12.5px, 7.5px 7.5px, 12.5px 12.5px, 7.5px 7.5px] 
+PASS CSS Transitions: property <background-size> from [] to [20px 20px, 0px 0px] at (0.5) is [15px 15px, 5px 5px, 15px 15px, 5px 5px] 
+PASS CSS Transitions: property <background-size> from [] to [20px 20px, 0px 0px] at (0.75) is [17.5px 17.5px, 2.5px 2.5px, 17.5px 17.5px, 2.5px 2.5px] 
+PASS CSS Transitions: property <background-size> from [] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [] to [20px 20px, 0px 0px] at (1.25) is [22.5px 22.5px, 0px 0px, 22.5px 22.5px, 0px 0px] 
+FAIL CSS Transitions: property <background-size> from [initial] to [20px 20px, 0px 0px] at (-0.3) is [auto, auto, auto, auto] assert_equals: expected "20px 20px , 0px 0px , 20px 20px , 0px 0px " but got "auto , auto , auto , auto "
+FAIL CSS Transitions: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0) is [auto, auto, auto, auto] assert_equals: expected "20px 20px , 0px 0px , 20px 20px , 0px 0px " but got "auto , auto , auto , auto "
+FAIL CSS Transitions: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0.3) is [auto, auto, auto, auto] assert_equals: expected "20px 20px , 0px 0px , 20px 20px , 0px 0px " but got "auto , auto , auto , auto "
+PASS CSS Transitions: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0.6) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [initial] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [initial] to [20px 20px, 0px 0px] at (1.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (-0.25) is [120px 120px, 125px 125px, 120px 120px, 125px 125px] 
+PASS CSS Transitions: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0) is [100px 100px, 100px 100px, 100px 100px, 100px 100px] 
+PASS CSS Transitions: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0.25) is [80px 80px, 75px 75px, 80px 80px, 75px 75px] 
+PASS CSS Transitions: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0.5) is [60px 60px, 50px 50px, 60px 60px, 50px 50px] 
+PASS CSS Transitions: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0.75) is [40px 40px, 25px 25px, 40px 40px, 25px 25px] 
+PASS CSS Transitions: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (1.25) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+FAIL CSS Transitions: property <background-size> from [unset] to [20px 20px, 0px 0px] at (-0.3) is [auto, auto, auto, auto] assert_equals: expected "20px 20px , 0px 0px , 20px 20px , 0px 0px " but got "auto , auto , auto , auto "
+FAIL CSS Transitions: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0) is [auto, auto, auto, auto] assert_equals: expected "20px 20px , 0px 0px , 20px 20px , 0px 0px " but got "auto , auto , auto , auto "
+FAIL CSS Transitions: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0.3) is [auto, auto, auto, auto] assert_equals: expected "20px 20px , 0px 0px , 20px 20px , 0px 0px " but got "auto , auto , auto , auto "
+PASS CSS Transitions: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0.6) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [unset] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [unset] to [20px 20px, 0px 0px] at (1.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (-0.3) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0.3) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0.5) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0.6) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (1) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (1.5) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (-0.3) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0.3) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0.5) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0.6) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (1) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (1.5) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (-0.25) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0.25) is [5px 5px, 10px 10px, 15px 15px, 25px 25px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0.5) is [10px 10px, 20px 20px, 30px 30px, 50px 50px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0.75) is [15px 15px, 30px 30px, 45px 45px, 75px 75px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (1) is [20px 20px, 40px 40px, 60px 60px, 100px 100px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (1.25) is [25px 25px, 50px 50px, 75px 75px, 125px 125px] 
+PASS CSS Transitions: property <background-size> from [0px 0px] to [80px 80px] at (-0.25) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [0px 0px] to [80px 80px] at (0) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS CSS Transitions: property <background-size> from [0px 0px] to [80px 80px] at (0.25) is [20px 20px, 20px 20px, 20px 20px, 20px 20px] 
+PASS CSS Transitions: property <background-size> from [0px 0px] to [80px 80px] at (0.5) is [40px 40px, 40px 40px, 40px 40px, 40px 40px] 
+PASS CSS Transitions: property <background-size> from [0px 0px] to [80px 80px] at (0.75) is [60px 60px, 60px 60px, 60px 60px, 60px 60px] 
+PASS CSS Transitions: property <background-size> from [0px 0px] to [80px 80px] at (1) is [80px 80px, 80px 80px, 80px 80px, 80px 80px] 
+PASS CSS Transitions: property <background-size> from [0px 0px] to [80px 80px] at (1.25) is [100px 100px, 100px 100px, 100px 100px, 100px 100px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (-0.25) is [0px 0px, 80px 0px, 0px 0px, 90px 0px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0) is [0px 0px, 80px 0px, 0px 0px, 80px 0px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0.25) is [10px 10px, 80px 20px, 0px 20px, 70px 10px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0.5) is [20px 20px, 80px 40px, 0px 40px, 60px 20px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0.75) is [30px 30px, 80px 60px, 0px 60px, 50px 30px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (1) is [40px 40px, 80px 80px, 0px 80px, 40px 40px] 
+PASS CSS Transitions: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (1.25) is [50px 50px, 80px 100px, 0px 100px, 30px 50px] 
+PASS CSS Animations: property <background-size> from [] to [20px 20px, 0px 0px] at (-0.25) is [7.5px 7.5px, 12.5px 12.5px, 7.5px 7.5px, 12.5px 12.5px] 
+PASS CSS Animations: property <background-size> from [] to [20px 20px, 0px 0px] at (0) is [10px 10px, 10px 10px, 10px 10px, 10px 10px] 
+PASS CSS Animations: property <background-size> from [] to [20px 20px, 0px 0px] at (0.25) is [12.5px 12.5px, 7.5px 7.5px, 12.5px 12.5px, 7.5px 7.5px] 
+PASS CSS Animations: property <background-size> from [] to [20px 20px, 0px 0px] at (0.5) is [15px 15px, 5px 5px, 15px 15px, 5px 5px] 
+PASS CSS Animations: property <background-size> from [] to [20px 20px, 0px 0px] at (0.75) is [17.5px 17.5px, 2.5px 2.5px, 17.5px 17.5px, 2.5px 2.5px] 
+PASS CSS Animations: property <background-size> from [] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [] to [20px 20px, 0px 0px] at (1.25) is [22.5px 22.5px, 0px 0px, 22.5px 22.5px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (-0.3) is [auto, auto, auto, auto] 
+PASS CSS Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0) is [auto, auto, auto, auto] 
+PASS CSS Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0.3) is [auto, auto, auto, auto] 
+PASS CSS Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0.6) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (1.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (-0.25) is [120px 120px, 125px 125px, 120px 120px, 125px 125px] 
+PASS CSS Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0) is [100px 100px, 100px 100px, 100px 100px, 100px 100px] 
+PASS CSS Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0.25) is [80px 80px, 75px 75px, 80px 80px, 75px 75px] 
+PASS CSS Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0.5) is [60px 60px, 50px 50px, 60px 60px, 50px 50px] 
+PASS CSS Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0.75) is [40px 40px, 25px 25px, 40px 40px, 25px 25px] 
+PASS CSS Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (1.25) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (-0.3) is [auto, auto, auto, auto] 
+PASS CSS Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0) is [auto, auto, auto, auto] 
+PASS CSS Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0.3) is [auto, auto, auto, auto] 
+PASS CSS Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0.6) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (1.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (-0.3) is [0px 0px, 0px 0px, contain, cover] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0) is [0px 0px, 0px 0px, contain, cover] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0.3) is [0px 0px, 0px 0px, contain, cover] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0.5) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0.6) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (1) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (1.5) is [40px 40px, 40px 40px, contain, cover] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (-0.3) is [0px 0px, 0px 0px, contain, cover] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0) is [0px 0px, 0px 0px, contain, cover] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0.3) is [0px 0px, 0px 0px, contain, cover] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0.5) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0.6) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (1) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (1.5) is [40px 40px, 40px 40px, cover, contain] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (-0.25) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0.25) is [5px 5px, 10px 10px, 15px 15px, 25px 25px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0.5) is [10px 10px, 20px 20px, 30px 30px, 50px 50px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0.75) is [15px 15px, 30px 30px, 45px 45px, 75px 75px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (1) is [20px 20px, 40px 40px, 60px 60px, 100px 100px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (1.25) is [25px 25px, 50px 50px, 75px 75px, 125px 125px] 
+PASS CSS Animations: property <background-size> from [0px 0px] to [80px 80px] at (-0.25) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [0px 0px] to [80px 80px] at (0) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS CSS Animations: property <background-size> from [0px 0px] to [80px 80px] at (0.25) is [20px 20px, 20px 20px, 20px 20px, 20px 20px] 
+PASS CSS Animations: property <background-size> from [0px 0px] to [80px 80px] at (0.5) is [40px 40px, 40px 40px, 40px 40px, 40px 40px] 
+PASS CSS Animations: property <background-size> from [0px 0px] to [80px 80px] at (0.75) is [60px 60px, 60px 60px, 60px 60px, 60px 60px] 
+PASS CSS Animations: property <background-size> from [0px 0px] to [80px 80px] at (1) is [80px 80px, 80px 80px, 80px 80px, 80px 80px] 
+PASS CSS Animations: property <background-size> from [0px 0px] to [80px 80px] at (1.25) is [100px 100px, 100px 100px, 100px 100px, 100px 100px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (-0.25) is [0px 0px, 80px 0px, 0px 0px, 90px 0px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0) is [0px 0px, 80px 0px, 0px 0px, 80px 0px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0.25) is [10px 10px, 80px 20px, 0px 20px, 70px 10px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0.5) is [20px 20px, 80px 40px, 0px 40px, 60px 20px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0.75) is [30px 30px, 80px 60px, 0px 60px, 50px 30px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (1) is [40px 40px, 80px 80px, 0px 80px, 40px 40px] 
+PASS CSS Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (1.25) is [50px 50px, 80px 100px, 0px 100px, 30px 50px] 
+PASS Web Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (-0.3) is [auto, auto, auto, auto] 
+PASS Web Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0) is [auto, auto, auto, auto] 
+PASS Web Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0.3) is [auto, auto, auto, auto] 
+PASS Web Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS Web Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (0.6) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS Web Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS Web Animations: property <background-size> from [initial] to [20px 20px, 0px 0px] at (1.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS Web Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (-0.25) is [120px 120px, 125px 125px, 120px 120px, 125px 125px] 
+PASS Web Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0) is [100px 100px, 100px 100px, 100px 100px, 100px 100px] 
+PASS Web Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0.25) is [80px 80px, 75px 75px, 80px 80px, 75px 75px] 
+PASS Web Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0.5) is [60px 60px, 50px 50px, 60px 60px, 50px 50px] 
+PASS Web Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (0.75) is [40px 40px, 25px 25px, 40px 40px, 25px 25px] 
+PASS Web Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS Web Animations: property <background-size> from [inherit] to [20px 20px, 0px 0px] at (1.25) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS Web Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (-0.3) is [auto, auto, auto, auto] 
+PASS Web Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0) is [auto, auto, auto, auto] 
+PASS Web Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0.3) is [auto, auto, auto, auto] 
+PASS Web Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS Web Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (0.6) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS Web Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (1) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS Web Animations: property <background-size> from [unset] to [20px 20px, 0px 0px] at (1.5) is [20px 20px, 0px 0px, 20px 20px, 0px 0px] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (-0.3) is [0px 0px, 0px 0px, contain, cover] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0) is [0px 0px, 0px 0px, contain, cover] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0.3) is [0px 0px, 0px 0px, contain, cover] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0.5) is [40px 40px, 40px 40px, contain, cover] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (0.6) is [40px 40px, 40px 40px, contain, cover] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (1) is [40px 40px, 40px 40px, contain, cover] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, contain, cover] at (1.5) is [40px 40px, 40px 40px, contain, cover] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (-0.3) is [0px 0px, 0px 0px, contain, cover] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0) is [0px 0px, 0px 0px, contain, cover] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0.3) is [0px 0px, 0px 0px, contain, cover] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0.5) is [40px 40px, 40px 40px, cover, contain] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (0.6) is [40px 40px, 40px 40px, cover, contain] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (1) is [40px 40px, 40px 40px, cover, contain] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, contain, cover] to [40px 40px, 40px 40px, cover, contain] at (1.5) is [40px 40px, 40px 40px, cover, contain] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (-0.25) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0.25) is [5px 5px, 10px 10px, 15px 15px, 25px 25px] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0.5) is [10px 10px, 20px 20px, 30px 30px, 50px 50px] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (0.75) is [15px 15px, 30px 30px, 45px 45px, 75px 75px] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (1) is [20px 20px, 40px 40px, 60px 60px, 100px 100px] 
+PASS Web Animations: property <background-size> from [0px 0px, 0px 0px, 0px 0px, 0px 0px] to [20px 20px, 40px 40px, 60px 60px, 100px 100px] at (1.25) is [25px 25px, 50px 50px, 75px 75px, 125px 125px] 
+PASS Web Animations: property <background-size> from [0px 0px] to [80px 80px] at (-0.25) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS Web Animations: property <background-size> from [0px 0px] to [80px 80px] at (0) is [0px 0px, 0px 0px, 0px 0px, 0px 0px] 
+PASS Web Animations: property <background-size> from [0px 0px] to [80px 80px] at (0.25) is [20px 20px, 20px 20px, 20px 20px, 20px 20px] 
+PASS Web Animations: property <background-size> from [0px 0px] to [80px 80px] at (0.5) is [40px 40px, 40px 40px, 40px 40px, 40px 40px] 
+PASS Web Animations: property <background-size> from [0px 0px] to [80px 80px] at (0.75) is [60px 60px, 60px 60px, 60px 60px, 60px 60px] 
+PASS Web Animations: property <background-size> from [0px 0px] to [80px 80px] at (1) is [80px 80px, 80px 80px, 80px 80px, 80px 80px] 
+PASS Web Animations: property <background-size> from [0px 0px] to [80px 80px] at (1.25) is [100px 100px, 100px 100px, 100px 100px, 100px 100px] 
+PASS Web Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (-0.25) is [0px 0px, 80px 0px, 0px 0px, 90px 0px] 
+PASS Web Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0) is [0px 0px, 80px 0px, 0px 0px, 80px 0px] 
+PASS Web Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0.25) is [10px 10px, 80px 20px, 0px 20px, 70px 10px] 
+PASS Web Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0.5) is [20px 20px, 80px 40px, 0px 40px, 60px 20px] 
+PASS Web Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (0.75) is [30px 30px, 80px 60px, 0px 60px, 50px 30px] 
+PASS Web Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (1) is [40px 40px, 80px 80px, 0px 80px, 40px 40px] 
+PASS Web Animations: property <background-size> from [0px 0px, 80px 0px] to [40px 40px, 80px 80px, 0px 80px] at (1.25) is [50px 50px, 80px 100px, 0px 100px, 30px 50px] 
+Harness: the test ran to completion.
+