Move mojo/public/c/environment/tests to mojo/public/c/tests/environment.

mojo/public/c/environment/tests/BUILD.gn

Index: mojo/public/c/environment/tests/BUILD.gn
diff --git a/mojo/public/c/environment/tests/BUILD.gn b/mojo/public/c/environment/tests/BUILD.gn
deleted file mode 100644
index 51a31c323a12c0ea1d68e72b62a76183664bfabf..0000000000000000000000000000000000000000
--- a/mojo/public/c/environment/tests/BUILD.gn
+++ /dev/null
@@ -1,20 +0,0 @@
-# Copyright 2016 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-import("../../../mojo_sdk.gni")
-
-mojo_sdk_source_set("perftest_helpers") {
-  testonly = true
-
-  sources = [
-    "async_waiter_perftest_helpers.cc",
-    "async_waiter_perftest_helpers.h",
-  ]
-
-  mojo_sdk_deps = [
-    "mojo/public/c:environment",
-    "mojo/public/c:system",
-    "mojo/public/cpp/system",
-  ]
-}