Move scoped_test_dir.* and test_io_thread.* from edk/test to edk/system/test.

mojo/edk/system/test/scoped_test_dir.h

Index: mojo/edk/system/test/scoped_test_dir.h
diff --git a/mojo/edk/test/scoped_test_dir.h b/mojo/edk/system/test/scoped_test_dir.h
similarity index 79%
rename from mojo/edk/test/scoped_test_dir.h
rename to mojo/edk/system/test/scoped_test_dir.h
index 4db372ff3e43934b9fdba5723ce0c0cd0e3e5c47..9f4db1bb3d2d2d0e8e3cb6004d2721f3ec510ce4 100644
--- a/mojo/edk/test/scoped_test_dir.h
+++ b/mojo/edk/system/test/scoped_test_dir.h
@@ -2,14 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef MOJO_EDK_TEST_SCOPED_TEST_DIR_H_
-#define MOJO_EDK_TEST_SCOPED_TEST_DIR_H_
+#ifndef MOJO_EDK_SYSTEM_TEST_SCOPED_TEST_DIR_H_
+#define MOJO_EDK_SYSTEM_TEST_SCOPED_TEST_DIR_H_
 
 #include "base/files/scoped_temp_dir.h"
 #include "mojo/edk/util/scoped_file.h"
 #include "mojo/public/cpp/system/macros.h"
 
 namespace mojo {
+namespace system {
 namespace test {
 
 // Creates/destroyes a temporary directory for test purposes. (Unlike
@@ -28,6 +29,7 @@ class ScopedTestDir {
 };
 
 }  // namespace test
+}  // namespace system
 }  // namespace mojo
 
-#endif  // MOJO_EDK_TEST_SCOPED_TEST_DIR_H_
+#endif  // MOJO_EDK_SYSTEM_TEST_SCOPED_TEST_DIR_H_