Replace CSSParserString with StringView.

third_party/WebKit/Source/core/css/parser/CSSParser.cpp

 // Copyright 2014 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/parser/CSSParser.h"
 
 #include "core/css/CSSColorValue.h"
 #include "core/css/CSSKeyframeRule.h"
 #include "core/css/StyleColor.h"
 #include "core/css/StylePropertySet.h"
@@ skipping 140 matching lines @@
         value = parseSingleValue(CSSPropertyColor, string, strictCSSParserContext());
 
     if (!value || !value->isColorValue())
         return false;
     color = toCSSColorValue(*value).value();
     return true;
 }
 
 bool CSSParser::parseSystemColor(Color& color, const String& colorString)
 {
-    CSSParserString cssColor;
-    cssColor.init(colorString);
-    CSSValueID id = cssValueKeywordID(cssColor);
+    CSSValueID id = cssValueKeywordID(colorString);
     if (!CSSPropertyParser::isSystemColor(id))
         return false;
 
     color = LayoutTheme::theme().systemColor(id);
     return true;
 }
 
 CSSValue* CSSParser::parseFontFaceDescriptor(CSSPropertyID propertyID, const String& propertyValue, const CSSParserContext& context)
 {
     StringBuilder builder;
     builder.appendLiteral("@font-face { ");
     builder.append(getPropertyNameString(propertyID));
     builder.appendLiteral(" : ");
     builder.append(propertyValue);
     builder.appendLiteral("; }");
     StyleRuleBase* rule = parseRule(context, nullptr, builder.toString());
     if (!rule || !rule->isFontFaceRule())
         return nullptr;
     return toStyleRuleFontFace(rule)->properties().getPropertyCSSValue(propertyID);
 }
 
 } // namespace blink