Revert "Add a Color class to dart:sky."

sky/engine/core/painting/CanvasColor.h

Index: sky/engine/core/painting/CanvasColor.h
diff --git a/sky/engine/core/painting/CanvasColor.h b/sky/engine/core/painting/CanvasColor.h
deleted file mode 100644
index 43e719c214b0a2ff589acaf0e1c1ee56b8f7bd37..0000000000000000000000000000000000000000
--- a/sky/engine/core/painting/CanvasColor.h
+++ /dev/null
@@ -1,31 +0,0 @@
-// 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.
-
-#ifndef SKY_ENGINE_CORE_PAINTING_CANVASCOLOR_H_
-#define SKY_ENGINE_CORE_PAINTING_CANVASCOLOR_H_
-
-#include "sky/engine/core/painting/Rect.h"
-#include "sky/engine/tonic/dart_wrappable.h"
-#include "sky/engine/wtf/PassRefPtr.h"
-#include "sky/engine/wtf/RefCounted.h"
-#include "third_party/skia/include/core/SkColor.h"
-
-namespace blink {
-
-class CanvasColor {
- public:
-  SkColor sk_color;
-};
-
-template<>
-struct DartConverter<CanvasColor, void> {
-  static CanvasColor FromArgumentsWithNullCheck(Dart_NativeArguments args,
-                                                int index,
-                                                Dart_Handle& exception);
-  static void SetReturnValue(Dart_NativeArguments args, unsigned val);
-};
-
-} // namespace blink
-
-#endif  // SKY_ENGINE_CORE_PAINTING_CANVASCOLOR_H_