Add support for CSSValue->CSSSimpleLength when it is a percentage.

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

 // Copyright 2016 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/StyleValueFactory.h"
 
 #include "core/css/CSSImageValue.h"
 #include "core/css/CSSValue.h"
 #include "core/css/cssom/CSSNumberValue.h"
 #include "core/css/cssom/CSSSimpleLength.h"
 #include "core/css/cssom/CSSStyleValue.h"
 #include "core/css/cssom/CSSStyleVariableReferenceValue.h"
 #include "core/css/cssom/CSSTransformValue.h"
 #include "core/css/cssom/CSSURLImageValue.h"
 #include "core/css/cssom/CSSUnparsedValue.h"
 #include "core/css/cssom/CSSUnsupportedStyleValue.h"
 
 namespace blink {
 
 namespace {
 
 CSSStyleValue* styleValueForPrimitiveValue(const CSSPrimitiveValue& primitiveValue)
 {
     if (primitiveValue.isNumber())
         return CSSNumberValue::create(primitiveValue.getDoubleValue());
-    if (primitiveValue.isLength())
+    if (primitiveValue.isLength() || primitiveValue.isPercentage())
         return CSSSimpleLength::fromCSSValue(primitiveValue);
 
     return nullptr;
 }
 
 CSSStyleValue* styleValueForProperty(CSSPropertyID propertyID, const CSSValue& value)
 {
     switch (propertyID) {
     case CSSPropertyTransform:
         return CSSTransformValue::fromCSSValue(value);
@@ skipping 40 matching lines @@
         styleValue = styleValueForProperty(propertyID, *innerValue);
         if (!styleValue) {
             return unsupportedCSSValue(value);
         }
         styleValueVector.append(styleValue);
     }
     return styleValueVector;
 }
 
 } // namespace blink