[css-ui] Make caret-color animatable

third_party/WebKit/Source/core/animation/CSSColorInterpolationType.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/animation/CSSColorInterpolationType.h"
 
 #include "core/animation/ColorPropertyFunctions.h"
 #include "core/css/CSSColorValue.h"
 #include "core/css/CSSIdentifierValue.h"
 #include "core/css/resolver/StyleResolverState.h"
@@ skipping 166 matching lines @@
 InterpolationValue CSSColorInterpolationType::maybeConvertNeutral(
     const InterpolationValue&,
     ConversionCheckers&) const {
   return convertStyleColorPair(StyleColor(Color::transparent),
                                StyleColor(Color::transparent));
 }
 
 InterpolationValue CSSColorInterpolationType::maybeConvertInitial(
     const StyleResolverState&,
     ConversionCheckers& conversionCheckers) const {
-  const StyleColor initialColor =
-      ColorPropertyFunctions::getInitialColor(cssProperty());
-  return convertStyleColorPair(initialColor, initialColor);
+  StyleColor initialColor;
+  if (ColorPropertyFunctions::getInitialColor(cssProperty(), initialColor))
+    return convertStyleColorPair(initialColor, initialColor);
+  return nullptr;
 }
 
 InterpolationValue CSSColorInterpolationType::maybeConvertInherit(
     const StyleResolverState& state,
     ConversionCheckers& conversionCheckers) const {
   if (!state.parentStyle())
     return nullptr;
   // Visited color can never explicitly inherit from parent visited color so
   // only use the unvisited color.
   const StyleColor inheritedColor = ColorPropertyFunctions::getUnvisitedColor(
@@ skipping 59 matching lines @@
           *colorPair.get(Unvisited), environment.state(), false,
           cssProperty() == CSSPropertyTextDecorationColor));
   ColorPropertyFunctions::setVisitedColor(
       cssProperty(), *environment.state().style(),
       resolveInterpolableColor(
           *colorPair.get(Visited), environment.state(), true,
           cssProperty() == CSSPropertyTextDecorationColor));
 }
 
 }  // namespace blink