'linux' platform should exclude 'chromeos' in json compiler.

tools/json_schema_compiler/test/function_platform_win_linux.json

Index: tools/json_schema_compiler/test/function_platform_win_linux.json
diff --git a/tools/json_schema_compiler/test/function_platform_win_linux.json b/tools/json_schema_compiler/test/function_platform_win_linux.json
new file mode 100644
index 0000000000000000000000000000000000000000..51a79c6d14b6cce2a2f88f7ede3dce07eb7168a6
--- /dev/null
+++ b/tools/json_schema_compiler/test/function_platform_win_linux.json
@@ -0,0 +1,16 @@
+// 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.
+
+[
+  {
+    "namespace": "json.compiler.test.functions",
+    "description": "",
+    "functions": [{
+      "name": "test",
+      "type": "function",
+      "platforms": ["win", "linux"],
+      "parameters": []
+    }]
+  }
+]