Upstream "nsurl_util.{h,mm}" from Chrome on iOS repository.

url/mac/url_conversions.h

+// Copyright 2012 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 URL_MAC_URL_CONVERSIONS_H_
+#define URL_MAC_URL_CONVERSIONS_H_
+
+#include "url/url_export.h"
+
+class GURL;
+@class NSURL;
+
+// This function must only be called on OSX 10.7+ or iOS 4+.
+// Method for creating a NSURL from a valid GURL. This method will return nil
+// if the |url| is not valid.
+// Note that NSURLs should *always* be created from GURLs, so that GURL
+// sanitization rules are applied everywhere.
+URL_EXPORT NSURL* NSURLWithGURL(const GURL& url);
+
+// This function must only be called on OSX 10.7+ or iOS 4+.
+// Method for creating a valid GURL from a NSURL. This method will return an
+// empty GURL if the |url| is nil.
+URL_EXPORT GURL GURLWithNSURL(NSURL* url);
+
+#endif  // URL_MAC_URL_CONVERSIONS_H_