Make the root_namespace argument to json_schema_compiler.gypi a string

tools/json_schema_compiler/test/json_schema_compiler_tests.gyp

 # Copyright (c) 2012 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.
 
 {
   'targets': [
     {
       'target_name': 'json_schema_compiler_tests',
       'type': 'static_library',
       'variables': {
@@ skipping 10 matching lines @@
           'functions_on_types.json',
           'idl_basics.idl',
           'idl_other_namespace.idl',
           'idl_other_namespace_sub_namespace.idl',
           'idl_object_types.idl',
           'objects.json',
           'simple_api.json',
           'error_generation.json'
         ],
         'cc_dir': 'tools/json_schema_compiler/test',
-        'root_namespace': 'test::api',
+        'root_namespace': 'test::api::%(namespace)s',
       },
       'inputs': [
         '<@(schema_files)',
       ],
       'sources': [
         '<@(schema_files)',
         'test_util.cc',
         'test_util.h',
       ],
       'includes': ['../../../build/json_schema_compile.gypi'],
       # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
       'msvs_disabled_warnings': [4267, ],
     },
   ],
 }