Implement ContentSecurityPolicy on the browser-side.

content/renderer/content_security_policy_util.h

+// Copyright 2017 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_RENDERER_CONTENT_SECURITY_POLICY_UTIL_H_
+#define CONTENT_RENDERER_CONTENT_SECURITY_POLICY_UTIL_H_
+
+#include "content/common/content_security_policy/content_security_policy.h"
+
+namespace blink {
+struct WebContentSecurityPolicyPolicy;
+}  // namespace blink
+
+namespace content {
+
+// Convert a WebContentSecurityPolicy into a ContentSecurityPolicy, these two
+// classes are the reflection of each other. One in content, the other in blink.
+ContentSecurityPolicy BuildContentSecurityPolicy(
+    const blink::WebContentSecurityPolicyPolicy&);
+
+}  // namespace content
+
+#endif /* CONTENT_RENDERER_CONTENT_SECURITY_POLICY_UTIL_H_ */