Add UseCounters for various standards-related code paths

src/js/i18n.js

Index: src/js/i18n.js
diff --git a/src/js/i18n.js b/src/js/i18n.js
index a859a9fbeb9f1028e0c6245364a800651d8e7f29..f914c032bb4793cdbb09b289207f9bb105461abf 100644
--- a/src/js/i18n.js
+++ b/src/js/i18n.js
@@ -33,6 +33,7 @@ var MakeTypeError;
 var MathFloor;
 var ObjectDefineProperties = utils.ImportNow("ObjectDefineProperties");
 var ObjectDefineProperty = utils.ImportNow("ObjectDefineProperty");
+var patternSymbol = utils.ImportNow("pattern_symbol");
 var RegExpTest;
 var StringIndexOf;
 var StringLastIndexOf;
@@ -41,6 +42,7 @@ var StringReplace;
 var StringSplit;
 var StringSubstr;
 var StringSubstring;
+const kIntlPattern = 15;
 
 utils.Import(function(from) {
   ArrayIndexOf = from.ArrayIndexOf;
@@ -1157,6 +1159,10 @@ function initializeNumberFormat(numberFormat, locales, options) {
     minimumFractionDigits: {writable: true},
     minimumIntegerDigits: {writable: true},
     numberingSystem: {writable: true},
+    pattern: {get() {
+      %IncrementUseCounter(kIntlPattern);
+      return this[patternSymbol];
+    }},
     requestedLocale: {value: requestedLocale, writable: true},
     style: {value: internalOptions.style, writable: true},
     useGrouping: {writable: true}
@@ -1561,7 +1567,11 @@ function initializeDateTimeFormat(dateFormat, locales, options) {
     minute: {writable: true},
     month: {writable: true},
     numberingSystem: {writable: true},
-    pattern: {writable: true},
+    [patternSymbol]: {writable: true},
+    pattern: {get() {

[adamk, 2016/01/05 19:10:09]

Don't you want a setter too, since the old property was writable?

[Dan Ehrenberg, 2016/01/06 03:20:55]

Oh, good point. Done.

+      %IncrementUseCounter(kIntlPattern);
+      return this[patternSymbol];
+    }},
     requestedLocale: {value: requestedLocale, writable: true},
     second: {writable: true},
     timeZone: {writable: true},
@@ -1638,7 +1648,7 @@ function initializeDateTimeFormat(dateFormat, locales, options) {
     };
 
     var format = this;
-    var fromPattern = fromLDMLString(format.resolved.pattern);
+    var fromPattern = fromLDMLString(format.resolved[patternSymbol]);
     var userCalendar = ICU_CALENDAR_MAP[format.resolved.calendar];
     if (IS_UNDEFINED(userCalendar)) {
       // Use ICU name if we don't have a match. It shouldn't happen, but