Prase IDL files in common/extensions/api PRESUBMIT check.

chrome/common/extensions/api/test_presubmit/valid_json.json

Index: chrome/common/extensions/api/test_presubmit/valid_json.json
diff --git a/chrome/common/extensions/api/test_presubmit/valid_json.json b/chrome/common/extensions/api/test_presubmit/valid_json.json
new file mode 100644
index 0000000000000000000000000000000000000000..615ea28d4bea44520eaacd7834304f5d01c3a639
--- /dev/null
+++ b/chrome/common/extensions/api/test_presubmit/valid_json.json
@@ -0,0 +1,11 @@
+// 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 a valid IDL file.
+
+// This is a comment.
+{
+  "key1": ["value1", "value2"],
+  "key2": 3  // This is an inline comment.
+}