Don't animate caret-color: auto

third_party/WebKit/Source/core/animation/ColorPropertyFunctions.h

Index: third_party/WebKit/Source/core/animation/ColorPropertyFunctions.h
diff --git a/third_party/WebKit/Source/core/animation/ColorPropertyFunctions.h b/third_party/WebKit/Source/core/animation/ColorPropertyFunctions.h
index 47fe8c79bf19301951cecf5a1d4496c732713f5e..bcec998b41b4f0f83a422c46bb995a1b0bf8c753 100644
--- a/third_party/WebKit/Source/core/animation/ColorPropertyFunctions.h
+++ b/third_party/WebKit/Source/core/animation/ColorPropertyFunctions.h
@@ -12,11 +12,35 @@ namespace blink {
 
 class ComputedStyle;
 
+struct OptionalStyleColor {
+ public:
+  OptionalStyleColor(std::nullptr_t) : m_isNull(true) {}
+  OptionalStyleColor(const StyleColor& styleColor)
+      : m_isNull(false), m_styleColor(styleColor) {}
+  OptionalStyleColor(const Color& color)
+      : m_isNull(false), m_styleColor(color) {}
+
+  bool isNull() const { return m_isNull; }
+  const StyleColor& access() const {
+    DCHECK(!m_isNull);
+    return m_styleColor;
+  }
+  bool operator==(const OptionalStyleColor& other) const {
+    return m_isNull == other.m_isNull && m_styleColor == other.m_styleColor;
+  }
+
+ private:
+  bool m_isNull;
+  StyleColor m_styleColor;
+};
+
 class ColorPropertyFunctions {
  public:
-  static bool getInitialColor(CSSPropertyID, StyleColor& initialColor);
-  static StyleColor getUnvisitedColor(CSSPropertyID, const ComputedStyle&);
-  static StyleColor getVisitedColor(CSSPropertyID, const ComputedStyle&);
+  static OptionalStyleColor getInitialColor(CSSPropertyID);
+  static OptionalStyleColor getUnvisitedColor(CSSPropertyID,
+                                              const ComputedStyle&);
+  static OptionalStyleColor getVisitedColor(CSSPropertyID,
+                                            const ComputedStyle&);
   static void setUnvisitedColor(CSSPropertyID, ComputedStyle&, const Color&);
   static void setVisitedColor(CSSPropertyID, ComputedStyle&, const Color&);
 };