Support compiling templates in the browser.

lib/src/template/utils.dart

Index: lib/src/template/utils.dart
diff --git a/lib/src/template/utils.dart b/lib/src/template/utils.dart
index 808ec6514c283fbe5c6b4209b395a2cdd808269d..8f68d0642fc7e47edfda1d824d6ab113d30dbffc 100644
--- a/lib/src/template/utils.dart
+++ b/lib/src/template/utils.dart
@@ -26,7 +26,7 @@ String toCamelCase(String hyphenedName) {
  * whatever [callback] returns. The log message will be printed if either
  * [:options.showInfo:] or [printTime] are true.
  */
-time(String logMessage, callback(), [bool printTime = false]) {
+time(String logMessage, callback(), {bool printTime: false}) {
   final watch = new Stopwatch();
   watch.start();
   var result = callback();
@@ -38,6 +38,25 @@ time(String logMessage, callback(), [bool printTime = false]) {
   return result;
 }
 
+/**
+ *  Invokes [callback], logs how long it takes from the moment [callback] is
+ *  executed until the future it returns is completed. Returns the future
+ *  returned by [callback]. The log message will be printed if either
+ *  [:options.showInfo:] or [printTime] are true.
+ */
+Future asyncTime(String logMessage, Future callback(),
+                 {bool printTime: false}) {
+  final watch = new Stopwatch();
+  watch.start();
+  return callback()..then((_) {
+    watch.stop();
+    final duration = watch.elapsedInMs();
+    if (options.showInfo || printTime) {
+      print('$logMessage in $GREEN_COLOR$duration ms$NO_COLOR');
+    }
+  });
+}
+
 // Color constants used for generating messages.
 final String GREEN_COLOR = '\u001b[32m';
 final String RED_COLOR = '\u001b[31m';