gfx: Converge scale precision related differences to single class.

ui/gfx/geometry/scale.h

+// Copyright (c) 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 UI_GFX_GEOMETRY_SCALE_H_
+#define UI_GFX_GEOMETRY_SCALE_H_
+
+#include "ui/gfx/gfx_export.h"
+
+namespace gfx {
+
+class GFX_EXPORT Scale {
+ public:
+  explicit Scale(float value);
+  explicit Scale(const Scale& other);
+
+  float Value() const { return value_; }
+  float AbsoluteValue() const { return absolute_value_; }
+
+  Scale& operator=(const Scale& other);
+  bool operator<(const Scale& other) const;
+  bool operator>(const Scale& other) const;
+
+ private:
+  float absolute_value_;
+  float value_;
+};
+
+inline bool operator==(const Scale& lhs, const Scale& rhs) {
+  return lhs.Value() == rhs.Value();
+}
+
+inline bool operator!=(const Scale& lhs, const Scale& rhs) {
+  return lhs.Value() != rhs.Value();
+}
+
+}  // namespace gfx
+
+#endif  // UI_GFX_GEOMETRY_SCALE_H_