Converted Observatory heap-profile element

runtime/observatory/lib/utils.dart

Index: runtime/observatory/lib/utils.dart
diff --git a/runtime/observatory/lib/utils.dart b/runtime/observatory/lib/utils.dart
index a69af5212ca8fa800ad967cd56f4edb6b81bff36..b8b5bb33bd9ff998e016a549cb417c29c2a89346 100644
--- a/runtime/observatory/lib/utils.dart
+++ b/runtime/observatory/lib/utils.dart
@@ -146,10 +146,16 @@ class Utils {
     return x.toStringAsFixed(2);
   }
 
-  static String formatDurationInSeconds(Duration x) {
-    return formatSeconds(x.inMilliseconds / Duration.MILLISECONDS_PER_SECOND);
+  static String formatMillis(double x) {
+    return x.toStringAsFixed(2);
   }
 
+  static String formatDurationInSeconds(Duration x) =>
+    formatSeconds(x.inMicroseconds / Duration.MICROSECONDS_PER_SECOND);
+
+  static String formatDurationInMilliseconds(Duration x) =>
+    formatMillis(x.inMicroseconds / Duration.MICROSECONDS_PER_MILLISECOND);
+
   static bool runningInJavaScript() => identical(1.0, 1);
 }