Add fromCSSValue methods to LengthValue subclasses, remove extra method in CSSSimpleLength.

third_party/WebKit/Source/core/css/cssom/CSSSimpleLength.h

Index: third_party/WebKit/Source/core/css/cssom/CSSSimpleLength.h
diff --git a/third_party/WebKit/Source/core/css/cssom/CSSSimpleLength.h b/third_party/WebKit/Source/core/css/cssom/CSSSimpleLength.h
index 7983f4e70a601bbbf8fe39bcbbeca24a0ba7368a..18ec13bf70114c288f8109c138e54d35f52d6340 100644
--- a/third_party/WebKit/Source/core/css/cssom/CSSSimpleLength.h
+++ b/third_party/WebKit/Source/core/css/cssom/CSSSimpleLength.h
@@ -5,31 +5,23 @@
 #ifndef CSSSimpleLength_h
 #define CSSSimpleLength_h
 
-#include "bindings/core/v8/ExceptionState.h"
 #include "core/css/cssom/CSSLengthValue.h"
 
 namespace blink {
 
 class CSSPrimitiveValue;
+class ExceptionState;
 
 class CORE_EXPORT CSSSimpleLength final : public CSSLengthValue {
     WTF_MAKE_NONCOPYABLE(CSSSimpleLength);
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static CSSSimpleLength* create(double value, const String& type, ExceptionState& exceptionState)
-    {
-        CSSPrimitiveValue::UnitType unit = unitFromName(type);
-        if (!isSupportedLengthUnit(unit)) {
-            exceptionState.throwTypeError("Invalid unit for CSSSimpleLength: " + type);
-            return nullptr;
-        }
-        return new CSSSimpleLength(value, unit);
-    }
-
+    static CSSSimpleLength* create(double, const String& type, ExceptionState&);
     static CSSSimpleLength* create(double value, CSSPrimitiveValue::UnitType type)
     {
         return new CSSSimpleLength(value, type);
     }
+    static CSSSimpleLength* fromCSSValue(const CSSPrimitiveValue&);
 
     bool containsPercent() const override;
 
@@ -37,8 +29,6 @@ public:
     String unit() const { return String(CSSPrimitiveValue::unitTypeToString(m_unit)); }
     CSSPrimitiveValue::UnitType lengthUnit() const { return m_unit; }
 
-    void setValue(double value) { m_value = value; }
-
     StyleValueType type() const override { return StyleValueType::SimpleLengthType; }
 
     CSSValue* toCSSValue() const override;