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

chrome/common/extensions/api/test_presubmit/invalid_idl_1.idl

Index: chrome/common/extensions/api/test_presubmit/invalid_idl_1.idl
diff --git a/chrome/common/extensions/api/test_presubmit/invalid_idl_1.idl b/chrome/common/extensions/api/test_presubmit/invalid_idl_1.idl
new file mode 100644
index 0000000000000000000000000000000000000000..32a048eee1cbb0676ae047b62cc7afe814a5199a
--- /dev/null
+++ b/chrome/common/extensions/api/test_presubmit/invalid_idl_1.idl
@@ -0,0 +1,12 @@
+// 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 an invalid IDL file.
+
+namespace test {
+  // Unexpected "{" after keyword "dictionary".
+  dictionary {
+    DOMString s;
+  };
+};