Remove system-provided temporary directory usage from test scripts.

tools/test.dart

Index: tools/test.dart
diff --git a/tools/test.dart b/tools/test.dart
index e362cc37430a3888de9d77cd1f2c2d5c7276969b..d15e0d7eee808532382c9f607d55d789d33955db 100755
--- a/tools/test.dart
+++ b/tools/test.dart
@@ -78,7 +78,6 @@ main() {
   var verbose = firstConf['verbose'];
   var printTiming = firstConf['time'];
   var listTests = firstConf['list'];
-  var keepGeneratedTests = firstConf['keep-generated-tests'];
 
   // Print the configurations being run by this execution of
   // test.dart. However, don't do it if the silent progress indicator
@@ -132,6 +131,5 @@ main() {
                                printTiming,
                                enqueueConfiguration,
                                verbose,
-                               listTests,
-                               keepGeneratedTests);
+                               listTests);
 }