Revert of Enforce capability spec renderer <--> browser

content/browser/mojo/merge_dictionary.h

-// 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.
-
-#ifndef CONTENT_BROWSER_MOJO_MERGE_DICTIONARY_H_
-#define CONTENT_BROWSER_MOJO_MERGE_DICTIONARY_H_
-
-#include "base/values.h"
-#include "content/common/content_export.h"
-
-namespace content {
-
-// Similar to base::DictionaryValue::MergeDictionary(), except concatenates
-// ListValue contents.
-// This is explicitly not part of base::DictionaryValue at brettw's request.
-void CONTENT_EXPORT MergeDictionary(base::DictionaryValue* target,
-                                    const base::DictionaryValue* source);
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_MOJO_MERGE_DICTIONARY_H_