cc: Do not create separate tilings for almost equal scale factors.

cc/base/math_util_unittest.cc

 // Copyright 2012 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 "cc/base/math_util.h"
 
 #include <cmath>
 
 #include "cc/test/geometry_test_utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ skipping 366 matching lines @@
   }
 }
 
 TEST(MathUtilTest, RoundDownUnderflow) {
   // Rounding down -123 by 50 is -150, which underflows int8_t, but fits in
   // int16_t.
   EXPECT_FALSE(MathUtil::VerifyRoundDown<int8_t>(-123, 50));
   EXPECT_TRUE(MathUtil::VerifyRoundDown<int16_t>(-123, 50));
 }
 
+TEST(MathUtilTest, AlmostEqualFloats) {
+  float f1 = 7.33907556533813f;
+  float f2 = 7.33907508850098f;
+  float f3 = MathUtil::RoundToFixedPrecision(f1);
+  float f4 = MathUtil::RoundToFixedPrecision(f2);
+  float f5 = MathUtil::RoundToFixedPrecision(2.33907508850098f);
+
+  EXPECT_TRUE(f1 != f2);
+  EXPECT_TRUE(f3 == f4);
+  EXPECT_FALSE(f3 == f5);
+}
+
 }  // namespace
 }  // namespace cc