Remove all usage of -webkit-*gradient inside blink

Source/devtools/front_end/spectrum.css

Index: Source/devtools/front_end/spectrum.css
diff --git a/Source/devtools/front_end/spectrum.css b/Source/devtools/front_end/spectrum.css
index e5aae8c6158a8ba7312c8bdb65c6fa28a67d8966..b9331fb3132192ddffe9036af5c100dd452e1dd3 100644
--- a/Source/devtools/front_end/spectrum.css
+++ b/Source/devtools/front_end/spectrum.css
@@ -75,15 +75,15 @@
 }
 
 .spectrum-sat {
-    background-image: -webkit-linear-gradient(left, white, rgba(204, 154, 129, 0));
+    background-image: linear-gradient(to right, white, rgba(204, 154, 129, 0));
 }
 
 .spectrum-val {
-    background-image: -webkit-linear-gradient(bottom, black, rgba(204, 154, 129, 0));
+    background-image: linear-gradient(to top, black, rgba(204, 154, 129, 0));
 }
 
 .spectrum-hue {
-    background: -webkit-linear-gradient(bottom, #ff0000 0%, #ffff00 17%, #00ff00 33%, #00ffff 50%, #0000ff 67%, #ff00ff 83%, #ff0000 100%);
+    background: linear-gradient(to top, #ff0000 0%, #ffff00 17%, #00ff00 33%, #00ffff 50%, #0000ff 67%, #ff00ff 83%, #ff0000 100%);
 }
 
 .spectrum-dragger {