Remove Animations and Transitions.

sky/engine/core/animation/DocumentAnimation.h

-// Copyright 2014 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_ANIMATION_DOCUMENTANIMATION_H_
-#define SKY_ENGINE_CORE_ANIMATION_DOCUMENTANIMATION_H_
-
-#include "sky/engine/core/dom/Document.h"
-
-namespace blink {
-
-class DocumentAnimation {
-public:
-    static AnimationTimeline* timeline(Document& document) { return &document.timeline(); }
-};
-
-} // namespace blink
-
-#endif  // SKY_ENGINE_CORE_ANIMATION_DOCUMENTANIMATION_H_