[polymer] Merge of master into polymer10-migration

tracing/tracing/base/math.html

Index: tracing/tracing/base/math.html
diff --git a/tracing/tracing/base/math.html b/tracing/tracing/base/math.html
index 59b5d3117b9987785db7005d8e2d1311cacdf85d..89d7ea472609d6338e11a56b6938aa754ca0fdad 100644
--- a/tracing/tracing/base/math.html
+++ b/tracing/tracing/base/math.html
@@ -31,6 +31,13 @@ found in the LICENSE file.
 'use strict';
 
 tr.exportTo('tr.b', function() {
+  /* Returns true when x and y are within delta of each other. */
+  function approximately(x, y, delta) {
+    if (delta === undefined)
+      delta = 1e-9;
+    return Math.abs(x - y) < delta;
+  }
+
   function clamp(x, lo, hi) {
     return Math.min(Math.max(x, lo), hi);
   }
@@ -156,6 +163,7 @@ tr.exportTo('tr.b', function() {
   };
 
   return {
+    approximately: approximately,
     clamp: clamp,
     lerp: lerp,
     normalize: normalize,