Make CSSPropertyParser::parseSingleValue return a const CSSValue*

third_party/WebKit/Source/core/animation/AnimationInputHelpers.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/animation/AnimationInputHelpers.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/SVGNames.h"
 #include "core/css/CSSValueList.h"
 #include "core/css/parser/CSSParser.h"
@@ skipping 192 matching lines @@
     return iter->value;
 }
 
 PassRefPtr<TimingFunction> AnimationInputHelpers::parseTimingFunction(const String& string, Document* document, ExceptionState& exceptionState)
 {
     if (string.isEmpty()) {
         exceptionState.throwTypeError("Easing may not be the empty string");
         return nullptr;
     }
 
-    CSSValue* value = CSSParser::parseSingleValue(CSSPropertyTransitionTimingFunction, string);
+    const CSSValue* value = CSSParser::parseSingleValue(CSSPropertyTransitionTimingFunction, string);
     if (!value || !value->isValueList()) {
         ASSERT(!value || value->isCSSWideKeyword());
         bool throwTypeError = true;
         if (document) {
             if (string.startsWith("function")) {
                 // Due to a bug in old versions of the web-animations-next
                 // polyfill, in some circumstances the string passed in here
                 // may be a Javascript function instead of the allowed values
                 // from the spec
                 // (http://w3c.github.io/web-animations/#dom-animationeffecttimingreadonly-easing)
@@ skipping 16 matching lines @@
         // throwTypeError bool and this if-statement should be removed after the
         // M53 branch point in July 2016, so that this case will also throw
         // TypeErrors from M54 onward.
         if (!throwTypeError) {
             return Timing::defaults().timingFunction;
         }
 
         exceptionState.throwTypeError("'" + string + "' is not a valid value for easing");
         return nullptr;
     }
-    CSSValueList* valueList = toCSSValueList(value);
+    const CSSValueList* valueList = toCSSValueList(value);
     if (valueList->length() > 1) {
         exceptionState.throwTypeError("Easing may not be set to a list of values");
         return nullptr;
     }
     return CSSToStyleMap::mapAnimationTimingFunction(valueList->item(0), true);
 }
 
 } // namespace blink