Split serialization tests further

tests/compiler/dart2js/serialization/test_helper.dart

Index: tests/compiler/dart2js/serialization/test_helper.dart
diff --git a/tests/compiler/dart2js/serialization/test_helper.dart b/tests/compiler/dart2js/serialization/test_helper.dart
index 9d3115f51e35ca794c3b51d5132d6968d835b442..2c74a07537fd33fd2087f5f17f42ddfcd6118dca 100644
--- a/tests/compiler/dart2js/serialization/test_helper.dart
+++ b/tests/compiler/dart2js/serialization/test_helper.dart
@@ -13,6 +13,7 @@ import 'package:compiler/src/elements/elements.dart';
 import 'package:compiler/src/serialization/equivalence.dart';
 import 'package:compiler/src/tree/nodes.dart';
 import 'package:expect/expect.dart';
+import 'test_data.dart';
 
 Check currentCheck;
 
@@ -589,3 +590,33 @@ void checkResolvedAsts(Compiler compiler1, Element member1,
   testResolvedAstEquivalence(
       resolvedAst1, resolvedAst2, const CheckStrategy());
 }
+
+/// Returns the test arguments for testing the [index]th skipped test. The
+/// [skip] count is used to check that [index] is a valid index.
+List<String> testSkipped(int index, int skip) {
+  if (index < 0 || index >= skip) {
+    throw new ArgumentError('Invalid skip index $index');
+  }
+  return ['${index}', '${index + 1}'];
+}
+
+/// Return the test arguments for testing the [index]th segment (1-based) of
+/// the [TESTS] split into [count] groups. The first [skip] tests are excluded
+/// from the automatic grouping.
+List<String> testSegment(int index, int count, int skip) {
+  if (index < 0 || index > count) {
+    throw new ArgumentError('Invalid segment index $index');
+  }
+
+  String segmentNumber(int i) {
+    return '${skip + i * (TESTS.length - skip) ~/ count}';
+  }
+
+  if (index == 1 && skip != 0) {
+    return ['${skip}', segmentNumber(index)];
+  } else if (index  == count) {
+    return [segmentNumber(index - 1)];
+  } else {
+    return [segmentNumber(index - 1), segmentNumber(index)];
+  }
+}