Update StyleValue.cssString() to use existing methods instead of rolling our own.

third_party/WebKit/Source/core/css/cssom/SimpleLength.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/cssom/SimpleLength.h"
 
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/css/cssom/StyleCalcLength.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace blink {
 
-String SimpleLength::cssString() const
-{
-    StringBuilder s;
-    s.appendNumber(m_value);
-    s.append(unit());
-    return s.toString();
-}
-
 PassRefPtrWillBeRawPtr<CSSValue> SimpleLength::toCSSValue() const
 {
-    // TODO: Don't re-parse the unit.
-    return cssValuePool().createValue(m_value, CSSPrimitiveValue::fromName(unit()));
+    return cssValuePool().createValue(m_value, LengthValue::lengthTypeToPrimitiveType(m_unit));
 }
 
 LengthValue* SimpleLength::addInternal(const LengthValue* other, ExceptionState& exceptionState)
 {
     const SimpleLength* o = toSimpleLength(other);
     if (m_unit == o->m_unit)
         return create(m_value + o->value(), m_unit);
 
     // Different units resolve to a calc.
     StyleCalcLength* result = StyleCalcLength::create(this, exceptionState);
@@ skipping 15 matching lines @@
 {
     return create(m_value * x, m_unit);
 }
 
 LengthValue* SimpleLength::divideInternal(double x, ExceptionState& exceptionState)
 {
     return create(m_value / x, m_unit);
 }
 
 } // namespace blink