Use 4 value syntax for getComputedStyle of background-position and -webkit-mask-position

LayoutTests/animations/interpolation/webkit-mask-position-interpolation.html

Index: LayoutTests/animations/interpolation/webkit-mask-position-interpolation.html
diff --git a/LayoutTests/animations/interpolation/webkit-mask-position-interpolation.html b/LayoutTests/animations/interpolation/webkit-mask-position-interpolation.html
index 1a8f65d4ca5fad3374eb5b43efd0a8c6b2ca9956..fccec8c996e98d46245ce6084c11b0257359e736 100644
--- a/LayoutTests/animations/interpolation/webkit-mask-position-interpolation.html
+++ b/LayoutTests/animations/interpolation/webkit-mask-position-interpolation.html
@@ -29,13 +29,13 @@ assertInterpolation({
   from: '0px 0px, 0px 0px, 0px 0px, 0px 0px',
   to: '80px 80px, 80px 80px, 80px 80px, 80px 80px',
 }, [
-  {at: -0.25, is: '-20px -20px, -20px -20px, -20px -20px, -20px -20px'},
-  {at: 0, is:     '  0px   0px,   0px   0px,   0px   0px,   0px   0px'},
-  {at: 0.25, is:  ' 20px  20px,  20px  20px,  20px  20px,  20px  20px'},
-  {at: 0.5, is:   ' 40px  40px,  40px  40px,  40px  40px,  40px  40px'},
-  {at: 0.75, is:  ' 60px  60px,  60px  60px,  60px  60px,  60px  60px'},
-  {at: 1, is:     ' 80px  80px,  80px  80px,  80px  80px,  80px  80px'},
-  {at: 1.25, is:  '100px 100px, 100px 100px, 100px 100px, 100px 100px'},
+  {at: -0.25, is: 'left -20px top -20px, left -20px top -20px, left -20px top -20px, left -20px top -20px'},
+  {at: 0, is:     'left   0px top   0px, left   0px top   0px, left   0px top   0px, left   0px top   0px'},
+  {at: 0.25, is:  'left  20px top  20px, left  20px top  20px, left  20px top  20px, left  20px top  20px'},
+  {at: 0.5, is:   'left  40px top  40px, left  40px top  40px, left  40px top  40px, left  40px top  40px'},
+  {at: 0.75, is:  'left  60px top  60px, left  60px top  60px, left  60px top  60px, left  60px top  60px'},
+  {at: 1, is:     'left  80px top  80px, left  80px top  80px, left  80px top  80px, left  80px top  80px'},
+  {at: 1.25, is:  'left 100px top 100px, left 100px top 100px, left 100px top 100px, left 100px top 100px'},
 ]);
 
 // Test single position value repeated over background images.
@@ -44,13 +44,13 @@ assertInterpolation({
   from: 'top 0px left 0px',
   to: 'left 80px top 80px',
 }, [
-  {at: -0.25, is: '-20px -20px, -20px -20px, -20px -20px, -20px -20px'},
-  {at: 0, is:     '  0px   0px,   0px   0px,   0px   0px,   0px   0px'},
-  {at: 0.25, is:  ' 20px  20px,  20px  20px,  20px  20px,  20px  20px'},
-  {at: 0.5, is:   ' 40px  40px,  40px  40px,  40px  40px,  40px  40px'},
-  {at: 0.75, is:  ' 60px  60px,  60px  60px,  60px  60px,  60px  60px'},
-  {at: 1, is:     ' 80px  80px,  80px  80px,  80px  80px,  80px  80px'},
-  {at: 1.25, is:  '100px 100px, 100px 100px, 100px 100px, 100px 100px'},
+  {at: -0.25, is: 'left -20px top -20px, left -20px top -20px, left -20px top -20px, left -20px top -20px'},
+  {at: 0, is:     'left   0px top   0px, left   0px top   0px, left   0px top   0px, left   0px top   0px'},
+  {at: 0.25, is:  'left  20px top  20px, left  20px top  20px, left  20px top  20px, left  20px top  20px'},
+  {at: 0.5, is:   'left  40px top  40px, left  40px top  40px, left  40px top  40px, left  40px top  40px'},
+  {at: 0.75, is:  'left  60px top  60px, left  60px top  60px, left  60px top  60px, left  60px top  60px'},
+  {at: 1, is:     'left  80px top  80px, left  80px top  80px, left  80px top  80px, left  80px top  80px'},
+  {at: 1.25, is:  'left 100px top 100px, left 100px top 100px, left 100px top 100px, left 100px top 100px'},
 ]);
 
 // Test mismatched numbers of position values.
@@ -59,13 +59,13 @@ assertInterpolation({
   from: '0px 0px, 80px 0px',
   to: '40px 40px, 80px 80px, 0px 80px',
 }, [
-  {at: -0.25, is: '-10px -10px, 80px -20px, 0px -20px, 90px -10px'},
-  {at: 0, is:     '  0px   0px, 80px   0px, 0px   0px, 80px   0px'},
-  {at: 0.25, is:  ' 10px  10px, 80px  20px, 0px  20px, 70px  10px'},
-  {at: 0.5, is:   ' 20px  20px, 80px  40px, 0px  40px, 60px  20px'},
-  {at: 0.75, is:  ' 30px  30px, 80px  60px, 0px  60px, 50px  30px'},
-  {at: 1, is:     ' 40px  40px, 80px  80px, 0px  80px, 40px  40px'},
-  {at: 1.25, is:  ' 50px  50px, 80px 100px, 0px 100px, 30px  50px'},
+  {at: -0.25, is: 'left -10px top -10px, left 80px top -20px, left 0px top -20px, left 90px top -10px'},
+  {at: 0, is:     'left   0px top   0px, left 80px top   0px, left 0px top   0px, left 80px top   0px'},
+  {at: 0.25, is:  'left  10px top  10px, left 80px top  20px, left 0px top  20px, left 70px top  10px'},
+  {at: 0.5, is:   'left  20px top  20px, left 80px top  40px, left 0px top  40px, left 60px top  20px'},
+  {at: 0.75, is:  'left  30px top  30px, left 80px top  60px, left 0px top  60px, left 50px top  30px'},
+  {at: 1, is:     'left  40px top  40px, left 80px top  80px, left 0px top  80px, left 40px top  40px'},
+  {at: 1.25, is:  'left  50px top  50px, left 80px top 100px, left 0px top 100px, left 30px top  50px'},
 ]);
 </script>
 </body>