Add new performance option

pkg/analyzer/lib/src/generated/engine.dart

Index: pkg/analyzer/lib/src/generated/engine.dart
diff --git a/pkg/analyzer/lib/src/generated/engine.dart b/pkg/analyzer/lib/src/generated/engine.dart
index 3e955cd4d8ffcd613a4062ba2432426adddf03f1..b16d920bcadaad410c9d757e5d045498284deb4b 100644
--- a/pkg/analyzer/lib/src/generated/engine.dart
+++ b/pkg/analyzer/lib/src/generated/engine.dart
@@ -9869,6 +9869,19 @@ class PerformanceStatistics {
    * The [TimeCounter] for time spent in hints generator.
    */
   static TimeCounter hints = new TimeCounter();
+
+  /**
+   * Reset all of the time counters to zero.
+   */
+  static void reset() {
+    io = new TimeCounter();
+    scan = new TimeCounter();
+    parse = new TimeCounter();
+    resolve = new TimeCounter();
+    angular = new TimeCounter();
+    errors = new TimeCounter();
+    hints = new TimeCounter();
+  }
 }
 
 /**