CC Animation: Extract PropertyAnimationState as a non-nested struct.

cc/animation/property_animation_state.h

+// Copyright 2016 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 CC_ANIMATION_PROPERTY_ANIMATION_STATE_H_
+#define CC_ANIMATION_PROPERTY_ANIMATION_STATE_H_
+
+#include "cc/base/cc_export.h"
+
+namespace cc {
+
+struct CC_EXPORT PropertyAnimationState {
+  bool currently_running_for_active_elements = false;
+  bool currently_running_for_pending_elements = false;
+  bool potentially_animating_for_active_elements = false;
+  bool potentially_animating_for_pending_elements = false;
+
+  bool operator==(const PropertyAnimationState& other) const;
+  bool operator!=(const PropertyAnimationState& other) const;
+
+  PropertyAnimationState& operator|=(const PropertyAnimationState& other);
+  PropertyAnimationState& operator^=(const PropertyAnimationState& other);
+
+  bool IsValid() const;
+
+  void Clear();
+};
+
+PropertyAnimationState operator^(const PropertyAnimationState& lhs,
+                                 const PropertyAnimationState& rhs);
+
+}  // namespace cc
+
+#endif  // CC_ANIMATION_PROPERTY_ANIMATION_STATE_H_