Reduce test.dart memory usage.

tools/testing/dart/test_suite.dart

Index: tools/testing/dart/test_suite.dart
diff --git a/tools/testing/dart/test_suite.dart b/tools/testing/dart/test_suite.dart
index 4a12b7a80afbf7db0e0a8e73d4225234a2a7d4cf..b6eaccdf7dcef008564a7efb9c52928c31eef066 100644
--- a/tools/testing/dart/test_suite.dart
+++ b/tools/testing/dart/test_suite.dart
@@ -50,7 +50,6 @@ typedef void CreateTest(Path filePath,
                         {bool isNegativeIfChecked,
                          bool hasCompileErrorIfChecked,
                          bool hasStaticWarning,
-                         Set<String> multitestOutcome,
                          String multitestKey,
                          Path originTestPath});
 
@@ -575,14 +574,12 @@ class TestInformation {
   bool isNegativeIfChecked;
   bool hasCompileErrorIfChecked;
   bool hasStaticWarning;
-  Set<String> multitestOutcome;
   String multitestKey;
 
   TestInformation(this.filePath, this.optionsFromFile,
                   this.hasCompileError, this.hasRuntimeError,
                   this.isNegativeIfChecked, this.hasCompileErrorIfChecked,
                   this.hasStaticWarning,
-                  this.multitestOutcome,
                   {this.multitestKey, this.originTestPath}) {
     assert(filePath.isAbsolute);
     if (originTestPath == null) originTestPath = filePath;
@@ -1025,7 +1022,6 @@ class StandardTestSuite extends TestSuite {
             {bool isNegativeIfChecked: false,
              bool hasCompileErrorIfChecked: false,
              bool hasStaticWarning: false,
-             Set<String> multitestOutcome: null,
              String multitestKey,
              Path originTestPath}) {
       // Cache the test information for each test case.
@@ -1036,7 +1032,6 @@ class StandardTestSuite extends TestSuite {
                                      isNegativeIfChecked,
                                      hasCompileErrorIfChecked,
                                      hasStaticWarning,
-                                     multitestOutcome,
                                      multitestKey: multitestKey,
                                      originTestPath: originTestPath);
       cachedTests.add(info);