[Media Router] Add MediaSink subtypes

chrome/browser/media/router/media_sink.h

 // 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 CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SINK_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SINK_H_
 
 #include <string>
 
 #include "base/optional.h"
 #include "third_party/icu/source/common/unicode/uversion.h"
 
 namespace U_ICU_NAMESPACE {
 class Collator;
 }  // namespace U_ICU_NAMESPACE
 
 namespace media_router {
 
 // Represents a sink to which media can be routed.
+// TODO(zhaobin): convert MediaSink into a struct.
 class MediaSink {
  public:
   using Id = std::string;
 
   // IconTypes are listed in the order in which sinks should be sorted.
   // The order must stay in sync with
   // chrome/browser/resources/media_router/media_router_data.js.
   enum IconType {
     CAST,
     CAST_AUDIO_GROUP,
@@ skipping 22 matching lines @@
   const base::Optional<std::string>& description() const {
     return description_;
   }
 
   void set_domain(const std::string& domain) { domain_ = domain; }
   const base::Optional<std::string>& domain() const { return domain_; }
 
   void set_icon_type(IconType icon_type) { icon_type_ = icon_type; }
   IconType icon_type() const { return icon_type_; }
 
+  // This method only compares IDs.
   bool Equals(const MediaSink& other) const;
 
+  // This method compares all fields.
+  bool operator==(const MediaSink& other) const;
+  bool operator!=(const MediaSink& other) const;
+
   // Compares |this| to |other| first by their icon types, then their names
   // using |collator|, and finally their IDs.
   bool CompareUsingCollator(const MediaSink& other,
                             const icu::Collator* collator) const;
 
   // For storing in sets and in maps as keys.
   struct Compare {
     bool operator()(const MediaSink& sink1, const MediaSink& sink2) const {
       return sink1.id() < sink2.id();
     }
@@ skipping 12 matching lines @@
   // Optional domain of the MediaSink.
   base::Optional<std::string> domain_;
 
   // The type of icon that corresponds with the MediaSink.
   IconType icon_type_ = IconType::GENERIC;
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SINK_H_