Add VR Shell animation classes and unit test.

chrome/browser/android/vr_shell/easing.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_EASING_H_
+#define CHROME_BROWSER_ANDROID_VR_SHELL_EASING_H_
+
+#include <cmath>
+
+#include "base/logging.h"

[bshe, 2016/09/12 15:38:26]

incorrect include? You probably just want base/macros.h

[cjgrant, 2016/09/13 17:32:16]

Done.

+#include "ui/gfx/geometry/cubic_bezier.h"

[bshe, 2016/09/12 15:38:26]

move this include to .cc?

[cjgrant, 2016/09/13 17:32:16]

This is needed for the CubicBezier type.

+
+namespace vr_shell {
+
+enum EasingType {
+  LINEAR = 0,
+  CUBICBEZIER,
+  EASEIN,
+  EASEOUT
+};
+
+class Easing {
+ public:
+  virtual double CalculateValue(double state) = 0;
+  virtual ~Easing() {}
+ protected:
+  Easing() {}
+  DISALLOW_COPY_AND_ASSIGN(Easing);

[bshe, 2016/09/12 15:38:26]

DISALLOW_COPY_AND_ASSIGN should be private

[cjgrant, 2016/09/13 17:32:15]

Done.

+};
+
+namespace easing {
+
+class CubicBezier : public Easing {
+ public:
+  CubicBezier(double p1x, double p1y, double p2x, double p2y);
+  double CalculateValue(double state) override;
+ private:
+  gfx::CubicBezier bezier;

[bshe, 2016/09/12 15:38:26]

nit: s/bezier/bezier_

[cjgrant, 2016/09/13 17:32:16]

Done.

+};
+
+class EaseIn : public Easing {
+ public:
+  explicit EaseIn(double power);
+  double CalculateValue(double state) override;
+ private:
+  double mPower;

[bshe, 2016/09/12 15:38:26]

nit: s/mPower/m_power_

[cjgrant, 2016/09/13 17:32:16]

Done (power_).

+};
+
+class EaseOut : public Easing {
+ public:
+  explicit EaseOut(double power);
+  double CalculateValue(double state) override;
+ private:
+  double mPower;

[bshe, 2016/09/12 15:38:26]

nit: s/mPower/m_power_

[cjgrant, 2016/09/13 17:32:16]

Done.

+};
+
+class Linear : public Easing {
+ public:
+  double CalculateValue(double state) override;
+};
+
+}  // namespace easing
+
+}  // namespace vr_shell
+
+#endif  // CHROME_BROWSER_ANDROID_VR_SHELL_EASING_H_