Remove the dependency on json schema compiler.

tools/json_schema_compiler/test/idl_namespace_chromeos.idl

Index: tools/json_schema_compiler/test/idl_namespace_chromeos.idl
diff --git a/tools/json_schema_compiler/test/idl_namespace_chromeos.idl b/tools/json_schema_compiler/test/idl_namespace_chromeos.idl
deleted file mode 100644
index ad748ff3b4c658288c0a956f20c9b09f31db0ee8..0000000000000000000000000000000000000000
--- a/tools/json_schema_compiler/test/idl_namespace_chromeos.idl
+++ /dev/null
@@ -1,10 +0,0 @@
-// Copyright 2013 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.
-
-// Tests the case of a namespace with chromeos platforms.
-
-[platforms=("chromeos")]
-namespace idl_namespace_chromeos {
-
-};