Don't run the "pkg" tests on the dart binary in the SDK.

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 38dc33d047c052f7dd90d9be015141dc39bb6064..475a3589c8ae153ad655ae5dd3c4736910b01315 100644
--- a/tools/testing/dart/test_suite.dart
+++ b/tools/testing/dart/test_suite.dart
@@ -108,10 +108,10 @@ abstract class TestSuite {
    * in the built SDK.
    */
   bool get useSdk {
-    // Some suites always use the SDK.
-    // TODO(rnystrom): Eventually, all tests should run out of the SDK and this
-    // check should go away.
-    if (['pkg', 'pub'].contains(suiteName)) return true;
+    // The pub suite always uses the SDK.
+    // TODO(rnystrom): Eventually, all test suites should run out of the SDK
+    // and this check should go away.
+    if (suiteName == 'pub') return true;
 
     return configuration['use_sdk'];
   }