Use <string> serialization rules for computed value of reference filter

third_party/WebKit/LayoutTests/animations/interpolation/backdrop-filter-interpolation-expected.txt

Index: third_party/WebKit/LayoutTests/animations/interpolation/backdrop-filter-interpolation-expected.txt
diff --git a/third_party/WebKit/LayoutTests/animations/interpolation/backdrop-filter-interpolation-expected.txt b/third_party/WebKit/LayoutTests/animations/interpolation/backdrop-filter-interpolation-expected.txt
index c9fd2c568f6cccf2aa93b12c95479331e3761a4d..5977c871da11fd30dfe23ea59fc56a5cc372c308 100644
--- a/third_party/WebKit/LayoutTests/animations/interpolation/backdrop-filter-interpolation-expected.txt
+++ b/third_party/WebKit/LayoutTests/animations/interpolation/backdrop-filter-interpolation-expected.txt
@@ -251,16 +251,16 @@ FAIL CSS Animations: property <backdrop-filter> from [none] to [sepia(1)] at (0)
 PASS CSS Animations: property <backdrop-filter> from [none] to [sepia(1)] at (0.5) is [sepia(0.5)] 
 PASS CSS Animations: property <backdrop-filter> from [none] to [sepia(1)] at (1) is [sepia(1)] 
 PASS CSS Animations: property <backdrop-filter> from [none] to [sepia(1)] at (1.5) is [sepia(1)] 
-PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (-0.3) is [url('#svgfilter')] 
-PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0) is [url('#svgfilter')] 
-PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0.3) is [url('#svgfilter')] 
+PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (-0.3) is [url("#svgfilter")] 
+PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0) is [url("#svgfilter")] 
+PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0.3) is [url("#svgfilter")] 
 PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0.5) is [none] 
 PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0.6) is [none] 
 PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (1) is [none] 
 PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (1.5) is [none] 
-PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (-0.3) is [url('#svgfilter')] 
-PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0) is [url('#svgfilter')] 
-PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0.3) is [url('#svgfilter')] 
+PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (-0.3) is [url("#svgfilter")] 
+PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0) is [url("#svgfilter")] 
+PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0.3) is [url("#svgfilter")] 
 PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0.5) is [blur(5px)] 
 PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0.6) is [blur(5px)] 
 PASS CSS Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (1) is [blur(5px)] 
@@ -380,16 +380,16 @@ FAIL Web Animations: property <backdrop-filter> from [none] to [sepia(1)] at (0)
 PASS Web Animations: property <backdrop-filter> from [none] to [sepia(1)] at (0.5) is [sepia(0.5)] 
 PASS Web Animations: property <backdrop-filter> from [none] to [sepia(1)] at (1) is [sepia(1)] 
 PASS Web Animations: property <backdrop-filter> from [none] to [sepia(1)] at (1.5) is [sepia(1)] 
-PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (-0.3) is [url('#svgfilter')] 
-PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0) is [url('#svgfilter')] 
-PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0.3) is [url('#svgfilter')] 
+PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (-0.3) is [url("#svgfilter")] 
+PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0) is [url("#svgfilter")] 
+PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0.3) is [url("#svgfilter")] 
 PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0.5) is [none] 
 PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (0.6) is [none] 
 PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (1) is [none] 
 PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [none] at (1.5) is [none] 
-PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (-0.3) is [url('#svgfilter')] 
-PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0) is [url('#svgfilter')] 
-PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0.3) is [url('#svgfilter')] 
+PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (-0.3) is [url("#svgfilter")] 
+PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0) is [url("#svgfilter")] 
+PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0.3) is [url("#svgfilter")] 
 PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0.5) is [blur(5px)] 
 PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (0.6) is [blur(5px)] 
 PASS Web Animations: property <backdrop-filter> from [url("#svgfilter")] to [blur(5px)] at (1) is [blur(5px)]