Move isValid/isCurrentColor from Color to StyleColor

Source/core/rendering/svg/RenderSVGResource.h

Index: Source/core/rendering/svg/RenderSVGResource.h
diff --git a/Source/core/rendering/svg/RenderSVGResource.h b/Source/core/rendering/svg/RenderSVGResource.h
index 5feaa1aab2199e23c3e31a7fa3e3b23584ef2ec0..e9bccc7f50f96bd2d137794d799a8153f5dd9ff2 100644
--- a/Source/core/rendering/svg/RenderSVGResource.h
+++ b/Source/core/rendering/svg/RenderSVGResource.h
@@ -76,8 +76,8 @@ public:
     }
 
     // Helper utilities used in the render tree to access resources used for painting shapes/text (gradients & patterns & solid colors only)
-    static RenderSVGResource* fillPaintingResource(RenderObject*, const RenderStyle*, Color& fallbackColor);
-    static RenderSVGResource* strokePaintingResource(RenderObject*, const RenderStyle*, Color& fallbackColor);
+    static RenderSVGResource* fillPaintingResource(RenderObject*, const RenderStyle*, StyleColor& fallbackColor);
+    static RenderSVGResource* strokePaintingResource(RenderObject*, const RenderStyle*, StyleColor& fallbackColor);
     static RenderSVGResourceSolidColor* sharedSolidPaintingResource();
 
     static void markForLayoutAndParentResourceInvalidation(RenderObject*, bool needsLayout = true);