Add safetymargin for timer tests in browsers.

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 836e5fcb782519281901e09e61f4115e3bf4b8f8..d225ba2680946b5c7ed406ced02176e8587aab90 100644
--- a/tests/lib/async/multiple_timer_test.dart
+++ b/tests/lib/async/multiple_timer_test.dart
@@ -12,6 +12,9 @@ const Duration TIMEOUT2 = const Duration(seconds: 2);
 const Duration TIMEOUT3 = const Duration(milliseconds: 500);
 const Duration TIMEOUT4 = const Duration(milliseconds: 1500);
 
+// Easy way to know if the test is compiled by dart2js.
+bool get isCompiledByDart2Js => identical(1, 1.0);
+

[ricow1, 2013/03/19 14:45:12]

how about:
bool get timerSafetyMargin => isCompiledByDart2Js ? 100 : 1;
and move the comments up here to not have the constants spread over the code

[floitsch, 2013/03/19 14:47:58]

Done.

 main() {
   test("multiple timer test", () {
     Stopwatch _stopwatch1 = new Stopwatch();
@@ -23,8 +26,10 @@ main() {
 
     void timeoutHandler1() {
       // The stopwatch is more precise than the Timer. It can happen that
-      // the TIMEOUT triggers *slightly* too early.
-      expect(_stopwatch1.elapsedMilliseconds + 1,
+      // the TIMEOUT triggers *slightly* too early on the VM.
+      // In the browser we have seen much worse variations.
+      int safetyMargin = isCompiledByDart2Js ? 100 : 1;
+      expect(_stopwatch1.elapsedMilliseconds + safetyMargin,
              greaterThanOrEqualTo(TIMEOUT1.inMilliseconds));
       expect(_order[_message], 0);
       _message++;
@@ -32,8 +37,10 @@ main() {
 
     void timeoutHandler2() {
       // The stopwatch is more precise than the Timer. It can happen that
-      // the TIMEOUT triggers *slightly* too early.
-      expect(_stopwatch2.elapsedMilliseconds + 1,
+      // the TIMEOUT triggers *slightly* too early on the VM.
+      // In the browser we have seen much worse variations.
+      int safetyMargin = isCompiledByDart2Js ? 100 : 1;
+      expect(_stopwatch2.elapsedMilliseconds + safetyMargin,
              greaterThanOrEqualTo(TIMEOUT2.inMilliseconds));
       expect(_order[_message], 1);
       _message++;
@@ -41,8 +48,10 @@ main() {
 
     void timeoutHandler3() {
       // The stopwatch is more precise than the Timer. It can happen that
-      // the TIMEOUT triggers *slightly* too early.
-      expect(_stopwatch3.elapsedMilliseconds + 1,
+      // the TIMEOUT triggers *slightly* too early on the VM.
+      // In the browser we have seen much worse variations.
+      int safetyMargin = isCompiledByDart2Js ? 100 : 1;
+      expect(_stopwatch3.elapsedMilliseconds + safetyMargin,
              greaterThanOrEqualTo(TIMEOUT3.inMilliseconds));
       expect(_order[_message], 2);
       _message++;
@@ -50,8 +59,10 @@ main() {
 
     void timeoutHandler4() {
       // The stopwatch is more precise than the Timer. It can happen that
-      // the TIMEOUT triggers *slightly* too early.
-      expect(_stopwatch4.elapsedMilliseconds + 1,
+      // the TIMEOUT triggers *slightly* too early on the VM.
+      // In the browser we have seen much worse variations.
+      int safetyMargin = isCompiledByDart2Js ? 100 : 1;
+      expect(_stopwatch4.elapsedMilliseconds + safetyMargin,
              greaterThanOrEqualTo(TIMEOUT4.inMilliseconds));
       expect(_order[_message], 3);
       _message++;