mojo/common: Decouple GURL dependency

mojo/common/url_type_converters.h

Index: mojo/common/url_type_converters.h
diff --git a/mojo/common/url_type_converters.h b/mojo/common/url_type_converters.h
new file mode 100644
index 0000000000000000000000000000000000000000..04390830795ef71c2b1bf5b25940a5604f7cd33f
--- /dev/null
+++ b/mojo/common/url_type_converters.h
@@ -0,0 +1,27 @@
+// 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 MOJO_COMMON_URL_TYPE_CONVERTERS_H_
+#define MOJO_COMMON_URL_TYPE_CONVERTERS_H_
+
+#include "third_party/mojo/src/mojo/public/cpp/bindings/string.h"
+#include "third_party/mojo/src/mojo/public/cpp/bindings/type_converter.h"
+
+class GURL;
+
+namespace mojo {
+
+template <>
+struct TypeConverter<String, GURL> {
+  static String Convert(const GURL& input);
+};
+
+template <>
+struct TypeConverter<GURL, String> {
+  static GURL Convert(const String& input);
+};
+
+}  // namespace mojo
+
+#endif  // MOJO_COMMON_URL_TYPE_CONVERTERS_H_