Split initial methods of margin on ComputedStyle.

third_party/WebKit/Source/core/css/CSSProperties.json5

Index: third_party/WebKit/Source/core/css/CSSProperties.json5
diff --git a/third_party/WebKit/Source/core/css/CSSProperties.json5 b/third_party/WebKit/Source/core/css/CSSProperties.json5
index eccec5441e4e39a870d8440f0bff60e9bd0e457b..8768e1fa4b253090a2e4446c12c7043919e07841 100644
--- a/third_party/WebKit/Source/core/css/CSSProperties.json5
+++ b/third_party/WebKit/Source/core/css/CSSProperties.json5
@@ -1264,7 +1264,6 @@
       api_class: "CSSPropertyAPIMargin",
       api_methods: ["parseSingleValue"],
       converter: "ConvertQuirkyLength",
-      initial: "InitialMargin",
       interpolable: true,
     },
     {
@@ -1272,7 +1271,6 @@
       api_class: "CSSPropertyAPIMargin",
       api_methods: ["parseSingleValue"],
       converter: "ConvertQuirkyLength",
-      initial: "InitialMargin",
       interpolable: true,
     },
     {
@@ -1280,7 +1278,6 @@
       api_class: "CSSPropertyAPIMargin",
       api_methods: ["parseSingleValue"],
       converter: "ConvertQuirkyLength",
-      initial: "InitialMargin",
       interpolable: true,
     },
     {
@@ -1288,7 +1285,6 @@
       api_class: "CSSPropertyAPIMargin",
       api_methods: ["parseSingleValue"],
       converter: "ConvertQuirkyLength",
-      initial: "InitialMargin",
       interpolable: true,
     },
     {