Support subpixel layout for borders.

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 1e8820da2aa7e7ff34af3f2bce82d2fb48096deb..0115fdbff06a2632152b6a4d04296ef4ce5bcdd9 100644
--- a/third_party/WebKit/Source/core/css/CSSProperties.json5
+++ b/third_party/WebKit/Source/core/css/CSSProperties.json5
@@ -602,7 +602,7 @@
     },
     {
       name: "border-bottom-width",
-      converter: "convertLineWidth<unsigned>",
+      converter: "convertLineWidth<float>",
       initial: "initialBorderWidth",
       interpolable: true,
     },
@@ -653,7 +653,7 @@
     },
     {
       name: "border-left-width",
-      converter: "convertLineWidth<unsigned>",
+      converter: "convertLineWidth<float>",
       initial: "initialBorderWidth",
       interpolable: true,
     },
@@ -669,7 +669,7 @@
     },
     {
       name: "border-right-width",
-      converter: "convertLineWidth<unsigned>",
+      converter: "convertLineWidth<float>",
       initial: "initialBorderWidth",
       interpolable: true,
     },
@@ -699,7 +699,7 @@
     },
     {
       name: "border-top-width",
-      converter: "convertLineWidth<unsigned>",
+      converter: "convertLineWidth<float>",
       initial: "initialBorderWidth",
       interpolable: true,
       keywords: ["thin", "medium", "thick"],