[Media Router] Parse device description xml in utility process

chrome/utility/media_router/dial_device_description_parser.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 CHROME_UTILITY_MEDIA_ROUTER_DIAL_DEVICE_DESCRIPTION_PARSER_H_
+#define CHROME_UTILITY_MEDIA_ROUTER_DIAL_DEVICE_DESCRIPTION_PARSER_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "chrome/common/media_router/dial_device_description.h"
+
+namespace media_router {
+
+class DialDeviceDescriptionParser {
+ public:
+  DialDeviceDescriptionParser();
+  ~DialDeviceDescriptionParser();
+
+  // Processes the result of getting device description. Returns true and
+  // populates corresponding fields in |dial_device_description_| if processing
+  // succeeds; otherwise returns false.
+  // |xml|: The device description.
+  bool Parse(const std::string& xml);
+
+  // Removes unique identifiers and serial number from the device description
+  // for logging. |xml|: The device description.
+  std::string ScrubXmlForLogging(const std::string& xml);
+
+  const media_router::DialDeviceDescription& device_description() {

[mark a. foltz, 2017/03/17 19:05:47]

This design means the caller has to keep the parser alive since it owns the
device description.

Also it means that calling this before parse returns a default-constructed
description which is not useful.

A more common pattern for parsing APIs is to pass a non-const pointer as an
output parameter; it's slightly less safe, but allows the caller to clearly own
the output.

It also means this parser doesn't have to be a class at all, saving an
allocation.

[zhaobin, 2017/03/18 00:17:39]

Done.

+    return device_description_;
+  }
+
+ private:
+  media_router::DialDeviceDescription device_description_;
+
+  DISALLOW_COPY_AND_ASSIGN(DialDeviceDescriptionParser);
+};
+
+}  // namespace media_router
+
+#endif  // CHROME_UTILITY_MEDIA_ROUTER_DIAL_DEVICE_DESCRIPTION_PARSER_H_