Add VR Shell animation classes and unit test.

chrome/browser/android/vr_shell/animation.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 CHROME_BROWSER_ANDROID_VR_SHELL_ANIMATION_H_
+#define CHROME_BROWSER_ANDROID_VR_SHELL_ANIMATION_H_
+
+#include <memory>
+#include <vector>
+
+#include "chrome/browser/android/vr_shell/easing.h"
+
+namespace vr_shell {
+
+// Describes the characteristics of a transition from an initial set of values
+// to a final set, with timing and interpolation information.  Other classes use
+// this information to animate UI element location, size, and other properties.
+class Animation {
+ public:
+  enum Property {
+    COPYRECT = 0,
+    SIZE,
+    TRANSLATION,
+    UNUSED,  // No longer used, available for a future type.
+    ROTATION,
+  };
+
+  Animation(int id,
+            Property property,
+            std::unique_ptr<easing::Easing> easing,
+            std::vector<float> from,
+            std::vector<float> to,
+            int64_t start,
+            int64_t duration);
+  ~Animation();
+
+  int id;
+  Property property;
+  std::unique_ptr<easing::Easing> easing;
+  std::vector<float> from;
+  std::vector<float> to;
+  int64_t start;
+  int64_t duration;
+};
+
+}  // namespace vr_shell
+
+#endif  // CHROME_BROWSER_ANDROID_VR_SHELL_ANIMATION_H_