Add a JSON sanitizer.

components/safe_json/json_sanitizer.h

Index: components/safe_json/json_sanitizer.h
diff --git a/components/safe_json/json_sanitizer.h b/components/safe_json/json_sanitizer.h
new file mode 100644
index 0000000000000000000000000000000000000000..3f393d55f2615812af1e86f697d7199011f6a9d8
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+++ b/components/safe_json/json_sanitizer.h
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+// Copyright 2015 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 COMPONENTS_SAFE_JSON_JSON_SANITIZER_H_
+#define COMPONENTS_SAFE_JSON_JSON_SANITIZER_H_
+
+#include <string>
+
+#include "base/callback_forward.h"
+#include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+
+#if defined(OS_ANDROID)
+#include <jni.h>
+#endif
+
+namespace safe_json {
+
+// Sanitizes and normalizes JSON by parsing it in a safe environment and
+// re-serializing it. Parsing the sanitized JSON should result in a value
+// identical to parsing the original JSON.
+// This allows parsing the sanitized JSON with the regular JSONParser while
+// reducing the risk versus parsing completely untrusted JSON. It also minifies
+// the resulting JSON, which might save some space.
+class JsonSanitizer {
+ public:
+  using StringCallback = base::Callback<void(const std::string&)>;
+
+  // Starts sanitizing the passed in unsafe JSON string. Either the passed
+  // |success_callback| or the |error_callback| will be called with the result
+  // of the sanitization or an error message, respectively, but not before the
+  // method returns.
+  static void Sanitize(const std::string& unsafe_json,
+                       const StringCallback& success_callback,
+                       const StringCallback& error_callback);
+
+#if defined(OS_ANDROID)
+  static bool Register(JNIEnv* env);
+#endif
+
+ protected:
+  JsonSanitizer() {}
+  ~JsonSanitizer() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(JsonSanitizer);
+};
+
+}  // namespace safe_json
+
+#endif  // COMPONENTS_SAFE_JSON_JSON_SANITIZER_H_