Revert "Try out 15 ms safety margin."

tests/lib/async/multiple_timer_test.dart

Index: tests/lib/async/multiple_timer_test.dart
diff --git a/tests/lib/async/multiple_timer_test.dart b/tests/lib/async/multiple_timer_test.dart
index 9556474c2bb7dad765946201f56c83c5dc9a9433..0a57ef012b6b496c46cc3de82f24bde4a84fef7c 100644
--- a/tests/lib/async/multiple_timer_test.dart
+++ b/tests/lib/async/multiple_timer_test.dart
@@ -18,8 +18,7 @@ const Duration TIMEOUT4 = const Duration(milliseconds: 1500);
 // Some browsers (Firefox and IE so far) can trigger too early. So we add more
 // margin. We use identical(1, 1.0) as an easy way to know if the test is
 // compiled by dart2js.
-// NOTE: 15 ms seems to be resolution of Stopwatch implementation on Windows.
-int get safetyMargin => identical(1, 1.0) ? 100 : 15;
+int get safetyMargin => identical(1, 1.0) ? 100 : 1;
 
 main() {
   test("multiple timer test", () {