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

cc/base/math_util.h

Index: cc/base/math_util.h
diff --git a/cc/base/math_util.h b/cc/base/math_util.h
index a83ab4fdce34be03b56fd23ffe978262abbe69fb..93bca234c126e5c27f3cd2b3c0358418772b2e43 100644
--- a/cc/base/math_util.h
+++ b/cc/base/math_util.h
@@ -97,6 +97,18 @@ class CC_EXPORT MathUtil {
     return (d > 0.0) ? std::floor(d + 0.5) : std::ceil(d - 0.5);
   }
 
+  // Rounds the given |value| to fixed precision. This makes amlost euqal

[vmpstr, 2015/10/19 18:58:38]

typo: amlost euqal -> almost equal

+  // floats (which differ by some threshold magnitude of floating point epsilon)
+  // to be considered as same.
+  // The |precision| should be >= 1 and
+  // <= (std::numeric_limits<float>::digits10 - 1), i.e. 5, as floating point
+  // precision of higher than that gives different values. For other
+  // |precision|, this function returns the same |value|.
+  // Examples:
+  // RoundToFixedPrecision(7.33907556533813, 4) returns 7.339000225067138671875.
+  // RoundToFixedPrecision(7.33907508850098, 4) returns 7.339000225067138671875.
+  static float RoundToFixedPrecision(float value, int precision);
+
   // Returns true if rounded up value does not overflow, false otherwise.
   template <typename T>
   static bool VerifyRoundup(T n, T mul) {