Add CSS conic-gradient calc() support

third_party/WebKit/LayoutTests/fast/gradients/conic-gradient-parsing.html

Index: third_party/WebKit/LayoutTests/fast/gradients/conic-gradient-parsing.html
diff --git a/third_party/WebKit/LayoutTests/fast/gradients/conic-gradient-parsing.html b/third_party/WebKit/LayoutTests/fast/gradients/conic-gradient-parsing.html
index df54ea66bacee742491018e397d4952b246e57cf..19230826b7a5886352b940147b6988126d73b76f 100644
--- a/third_party/WebKit/LayoutTests/fast/gradients/conic-gradient-parsing.html
+++ b/third_party/WebKit/LayoutTests/fast/gradients/conic-gradient-parsing.html
@@ -38,6 +38,10 @@
     { style: "conic-gradient(at top left from 0, black, white)"            , computed: "none" },
     { style: "conic-gradient(black 10% 20% 30%, white)"                    , computed: "none" },
     { style: "conic-gradient(black, 30% 50%, white)"                       , computed: "none" },
+    { style: "conic-gradient(from calc(10), black, white)"                 , computed: "none" },
+    { style: "conic-gradient(from calc(10deg + 20%), black, white)"        , computed: "none" },
+    { style: "conic-gradient(black calc(10), white)"                       , computed: "none" },
+    { style: "conic-gradient(black calc(10deg + 20%), white)"              , computed: "none" },
 
     { style: "conic-gradient(black, white)"           , computed: "conic-gradient(black, white)" },
     { style: "conic-gradient(black 0, white)"         , computed: "conic-gradient(black 0deg, white)" },
@@ -69,9 +73,16 @@
     { style: "conic-gradient(from 10deg, black, white)"          , computed: "conic-gradient(from 10deg, black, white)" },
     { style: "conic-gradient(from 10deg at center, black, white)", computed: "conic-gradient(from 10deg at center center, black, white)" },
 
-    { style: "conic-gradient(black 0%, 10%, green .5turn, 50%, white)", computed: "conic-gradient(black 0%, 10%, green 0.5turn, 50%, white)" },
+    { style: "conic-gradient(black 0%, 10%, green .5turn, 50%, white)"       , computed: "conic-gradient(black 0%, 10%, green 0.5turn, 50%, white)" },
     { style: "conic-gradient(black 0deg, 0%, green .5turn, 50%, white 1turn)", computed: "conic-gradient(black 0deg, 0%, green 0.5turn, 50%, white 1turn)" },
 
+    { style: "conic-gradient(from calc(10deg), black, white)"        , computed: "conic-gradient(from calc(10deg), black, white)" },
+    { style: "conic-gradient(from calc(10deg + 35deg), black, white)", computed: "conic-gradient(from calc(45deg), black, white)" },
+    { style: "conic-gradient(black calc(10deg), white)"              , computed: "conic-gradient(black calc(10deg), white)" },
+    { style: "conic-gradient(black calc(10deg + 20deg), white)"      , computed: "conic-gradient(black calc(30deg), white)" },
+    { style: "conic-gradient(black calc(10%), white)"                , computed: "conic-gradient(black calc(10%), white)" },
+    { style: "conic-gradient(black calc(10% + 20%), white)"          , computed: "conic-gradient(black calc(30%), white)" },
+
     // Examples from https://drafts.csswg.org/css-images-4/#conic-gradient-examples
     { style: "conic-gradient(#f06, gold)"                     , computed: "conic-gradient(rgb(255, 0, 102), gold)" },
     { style: "conic-gradient(at 50% 50%, #f06, gold)"         , computed: "conic-gradient(at 50% 50%, rgb(255, 0, 102), gold)" },