Animation: FilterStyleInterpolation for animating filter

LayoutTests/animations/interpolation/filter-interpolation.html

Index: LayoutTests/animations/interpolation/filter-interpolation.html
diff --git a/LayoutTests/animations/interpolation/filter-interpolation.html b/LayoutTests/animations/interpolation/filter-interpolation.html
index bacccd8ef294ea961ec2b00a3d0a423ec16b2e25..1e39e7ec8b7e30421cb436ad356e82843f90a32e 100644
--- a/LayoutTests/animations/interpolation/filter-interpolation.html
+++ b/LayoutTests/animations/interpolation/filter-interpolation.html
@@ -54,7 +54,7 @@ assertInterpolation({
   to: 'blur(10px) hue-rotate(180deg)'
 }, [
   {at: -0.5, is: 'blur(4px) hue-rotate(-90deg)'},
-  {at: 0, is: 'blur(6px)'},
+  {at: 0, is: 'blur(6px) hue-rotate(0deg)'},
   {at: 0.25, is: 'blur(7px) hue-rotate(45deg)'},
   {at: 0.5, is: 'blur(8px) hue-rotate(90deg)'},
   {at: 1, is: 'blur(10px) hue-rotate(180deg)'},
@@ -67,7 +67,7 @@ assertInterpolation({
   to: 'hue-rotate(180deg)'
 }, [
   {at: -0.5, is: 'hue-rotate(-90deg)'},
-  {at: 0, is: 'none'},
+  {at: 0, is: 'hue-rotate(0deg)'},
   {at: 0.25, is: 'hue-rotate(45deg)'},
   {at: 0.5, is: 'hue-rotate(90deg)'},
   {at: 1, is: 'hue-rotate(180deg)'},
@@ -83,7 +83,7 @@ assertInterpolation({
   {at: 0, is: 'hue-rotate(180deg)'},
   {at: 0.25, is: 'hue-rotate(135deg)'},
   {at: 0.5, is: 'hue-rotate(90deg)'},
-  {at: 1, is: 'none'},
+  {at: 1, is: 'hue-rotate(0deg)'},
   {at: 1.5, is: 'hue-rotate(-90deg)'},
 ]);
 
@@ -94,7 +94,7 @@ assertInterpolation({
   to: 'blur(10px)'
 }, [
   {at: -1, is: 'blur(0px)'}, // Negative values are not allowed.
-  {at: 0, is: 'none'},
+  {at: 0, is: 'blur(0px)'},
   {at: 0.5, is: 'blur(5px)'},
   {at: 1, is: 'blur(10px)'},
   {at: 1.5, is: 'blur(15px)'}
@@ -108,7 +108,7 @@ assertInterpolation({
   {at: -1, is: 'brightness(0)'}, // Negative values are not allowed.
   {at: 0, is: 'brightness(0)'},
   {at: 0.5, is: 'brightness(0.5)'},
-  {at: 1, is: 'none'},
+  {at: 1, is: 'brightness(1)'},
   {at: 1.5, is: 'brightness(1.5)'}
 ]);
 
@@ -120,7 +120,7 @@ assertInterpolation({
   {at: -1, is: 'contrast(0)'}, // Negative values are not allowed.
   {at: 0, is: 'contrast(0)'},
   {at: 0.5, is: 'contrast(0.5)'},
-  {at: 1, is: 'none'},
+  {at: 1, is: 'contrast(1)'},
   {at: 1.5, is: 'contrast(1.5)'}
 ]);
 
@@ -154,7 +154,7 @@ assertInterpolation({
   to: 'grayscale(1)'
 }, [
   {at: -1, is: 'grayscale(0)'}, // Negative values are not allowed.
-  {at: 0, is: 'none'},
+  {at: 0, is: 'grayscale(0)'},
   {at: 0.5, is: 'grayscale(0.5)'},
   {at: 1, is: 'grayscale(1)'},
   {at: 1.5, is: 'grayscale(1)'} // Should clamp values to 1.
@@ -166,7 +166,7 @@ assertInterpolation({
   to: 'hue-rotate(360deg)'
 }, [
   {at: -1, is: 'hue-rotate(-360deg)'},
-  {at: 0, is: 'none'},
+  {at: 0, is: 'hue-rotate(0deg)'},
   {at: 0.5, is: 'hue-rotate(180deg)'},
   {at: 1, is: 'hue-rotate(360deg)'},
   {at: 1.5, is: 'hue-rotate(540deg)'}
@@ -178,7 +178,7 @@ assertInterpolation({
   to: 'invert(1)'
 }, [
   {at: -1, is: 'invert(0)'}, // Negative values are not allowed.
-  {at: 0, is: 'none'},
+  {at: 0, is: 'invert(0)'},
   {at: 0.5, is: 'invert(0.5)'},
   {at: 1, is: 'invert(1)'},
   {at: 1.5, is: 'invert(1)'} // Should clamp values to 1.
@@ -192,7 +192,7 @@ assertInterpolation({
   {at: -1, is: 'opacity(0)'}, // Negative values are not allowed.
   {at: 0, is: 'opacity(0)'},
   {at: 0.5, is: 'opacity(0.5)'},
-  {at: 1, is: 'none'},
+  {at: 1, is: 'opacity(1)'},
   {at: 1.5, is: 'opacity(1)'} // Should clamp values to 1.
 ]);
 
@@ -204,7 +204,7 @@ assertInterpolation({
   {at: -1, is: 'saturate(0)'}, // Negative values are not allowed.
   {at: 0, is: 'saturate(0)'},
   {at: 0.5, is: 'saturate(0.5)'},
-  {at: 1, is: 'none'},
+  {at: 1, is: 'saturate(1)'},
   {at: 1.5, is: 'saturate(1.5)'}
 ]);
 
@@ -214,7 +214,7 @@ assertInterpolation({
   to: 'sepia(1)'
 }, [
   {at: -1, is: 'sepia(0)'}, // Negative values are not allowed.
-  {at: 0, is: 'none'},
+  {at: 0, is: 'sepia(0)'},
   {at: 0.5, is: 'sepia(0.5)'},
   {at: 1, is: 'sepia(1)'},
   {at: 1.5, is: 'sepia(1)'} // Should clamp values to 1.