gfx: Converge scale precision related differences to single class.

ui/gfx/geometry/scale_unittest.cc

+// 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.
+
+#include <limits>
+
+#include "base/command_line.h"
+#include "base/logging.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gfx/geometry/scale.h"
+#include "ui/gfx/switches.h"
+
+namespace gfx {
+
+TEST(ScaleTest, ScaleOperations) {
+  base::CommandLine::ForCurrentProcess()->AppendSwitch(
+      switches::kEnableFixedPrecisionScale);
+
+  Scale scale1(7.33907556533813f);
+  Scale scale2(7.33907508850098f);
+  Scale scale3(2.33907508850098f);
+
+  EXPECT_TRUE(scale1 == scale2);
+  EXPECT_FALSE(scale1 == scale3);
+
+  // For higher scale values (e.g. >= 10), the absolute values may get
+  // represented same as computed values.
+  EXPECT_FALSE(scale1.AbsoluteValue() == scale2.AbsoluteValue());
+
+  EXPECT_TRUE(scale2 != scale3);
+  EXPECT_TRUE(scale3 < scale1);
+  EXPECT_TRUE(scale1 > scale3);
+
+  scale3 = Scale(7.33907556533813f);
+  EXPECT_TRUE(scale1 == scale3);
+
+  Scale scale4(scale3);
+  EXPECT_TRUE(scale3 == scale4);
+}
+
+}  // namespace gfx