Revert r154797: "Move isValid/isCurrentColor from Color to StyleColor"

Source/core/rendering/style/StyleRareNonInheritedData.h

Index: Source/core/rendering/style/StyleRareNonInheritedData.h
diff --git a/Source/core/rendering/style/StyleRareNonInheritedData.h b/Source/core/rendering/style/StyleRareNonInheritedData.h
index 340357a1505ce22f84175c1e3016d639e9781fde..781b8ce665fc711d09cc5916cd03474f4ae2932e 100644
--- a/Source/core/rendering/style/StyleRareNonInheritedData.h
+++ b/Source/core/rendering/style/StyleRareNonInheritedData.h
@@ -25,7 +25,6 @@
 #ifndef StyleRareNonInheritedData_h
 #define StyleRareNonInheritedData_h
 
-#include "core/css/StyleColor.h"
 #include "core/rendering/ClipPathOperation.h"
 #include "core/rendering/style/BasicShapes.h"
 #include "core/rendering/style/CounterDirectives.h"
@@ -131,14 +130,14 @@ public:
 
     RefPtr<ClipPathOperation> m_clipPath;
 
-    StyleColor m_textDecorationColor;
-    StyleColor m_visitedLinkTextDecorationColor;
-    StyleColor m_visitedLinkBackgroundColor;
-    StyleColor m_visitedLinkOutlineColor;
-    StyleColor m_visitedLinkBorderLeftColor;
-    StyleColor m_visitedLinkBorderRightColor;
-    StyleColor m_visitedLinkBorderTopColor;
-    StyleColor m_visitedLinkBorderBottomColor;
+    Color m_textDecorationColor;
+    Color m_visitedLinkTextDecorationColor;
+    Color m_visitedLinkBackgroundColor;
+    Color m_visitedLinkOutlineColor;
+    Color m_visitedLinkBorderLeftColor;
+    Color m_visitedLinkBorderRightColor;
+    Color m_visitedLinkBorderTopColor;
+    Color m_visitedLinkBorderBottomColor;
 
     int m_order;