Restructure type tracking in StyleValues to work better with new numeric types

third_party/WebKit/Source/core/css/cssom/CSSUnitValue.idl

Index: third_party/WebKit/Source/core/css/cssom/CSSUnitValue.idl
diff --git a/third_party/WebKit/Source/core/css/cssom/CSSUnitValue.idl b/third_party/WebKit/Source/core/css/cssom/CSSUnitValue.idl
index 02ab6d4ebdc654e0f210ad0df029f1e99217cbc6..c00d6c4dc421876ec8f4008e9d8030ba09b9d85b 100644
--- a/third_party/WebKit/Source/core/css/cssom/CSSUnitValue.idl
+++ b/third_party/WebKit/Source/core/css/cssom/CSSUnitValue.idl
@@ -5,7 +5,6 @@
 // Represents numeric values that can be expressed as a single number plus a
 // unit (or a naked number or percentage).
 // https://drafts.css-houdini.org/css-typed-om/#cssunitvalue
-
 [
   Constructor(double value, DOMString unit),
   RaisesException=Constructor,
@@ -14,5 +13,5 @@
 ] interface CSSUnitValue : CSSNumericValue {
   [EnforceRange] attribute double value;
   [RaisesException=Setter] attribute DOMString unit;
-  [ImplementedAs=cssType] readonly attribute DOMString type;
+  readonly attribute DOMString type;
 };