[cast_channel] Make CastSocketService a global leaky singleton

components/cast_channel/cast_socket_service.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 COMPONENTS_CAST_CHANNEL_CAST_CHANNEL_SERVICE_H_
 #define COMPONENTS_CAST_CHANNEL_CAST_CHANNEL_SERVICE_H_
 
 #include <map>
 #include <memory>
 
 #include "base/macros.h"
+#include "base/memory/singleton.h"
 #include "base/threading/thread_checker.h"
 #include "components/cast_channel/cast_socket.h"
-#include "components/keyed_service/core/refcounted_keyed_service.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace cast_channel {
 
 // This class adds, removes, and returns cast sockets created by CastChannelAPI
 // to underlying storage.
 // Instance of this class is created on the UI thread and destroyed on the IO
 // thread. All public API must be called from the IO thread.
-class CastSocketService : public RefcountedKeyedService {
+class CastSocketService {
  public:
-  CastSocketService();
+  static CastSocketService* GetInstance();
 
   // Returns a pointer to the Logger member variable.
   scoped_refptr<cast_channel::Logger> GetLogger();
 
   // Adds |socket| to |sockets_| and returns raw pointer of |socket|. Takes
   // ownership of |socket|.
   CastSocket* AddSocket(std::unique_ptr<CastSocket> socket);
 
   // Removes the CastSocket corresponding to |channel_id| from the
   // CastSocketRegistry. Returns nullptr if no such CastSocket exists.
@@ skipping 34 matching lines @@
   // |ip_endpoint|: IP address and port of the remote host.
   // |net_log|: Log of socket events.
   // |open_cb|: OnOpenCallback invoked when cast socket is opened.
   // |observer|: Observer handles messages and errors on newly opened socket.
   // Does not take ownership of |observer|.
   virtual int OpenSocket(const net::IPEndPoint& ip_endpoint,
                          net::NetLog* net_log,
                          const CastSocket::OnOpenCallback& open_cb,
                          CastSocket::Observer* observer);
 
-  // Returns an observer corresponding to |id|.
-  CastSocket::Observer* GetObserver(const std::string& id);
-
-  // Adds |observer| to |socket_observer_map_| keyed by |id|. Return raw pointer
-  // of the newly added observer.
-  CastSocket::Observer* AddObserver(
-      const std::string& id,
-      std::unique_ptr<CastSocket::Observer> observer);
+  // Remove |observer| from each socket in |sockets_|
+  void RemoveObserver(CastSocket::Observer* observer);
 
   // Allow test to inject a mock cast socket.
   void SetSocketForTest(std::unique_ptr<CastSocket> socket_for_test);
 
- protected:
-  ~CastSocketService() override;
+ private:
+  friend class CastSocketServiceTest;
+  friend class MockCastSocketService;
+  friend struct base::DefaultSingletonTraits<CastSocketService>;
+  friend struct std::default_delete<CastSocketService>;
 
- private:
-  // RefcountedKeyedService implementation.
-  void ShutdownOnUIThread() override;
+  CastSocketService();
+  virtual ~CastSocketService();
 
   // Used to generate CastSocket id.
   static int last_channel_id_;
 
   // The collection of CastSocket keyed by channel_id.
   std::map<int, std::unique_ptr<CastSocket>> sockets_;
 
-  // Map of CastSocket::Observer keyed by observer id. For extension side
-  // observers, id is extension_id; For browser side observers, id is a hard
-  // coded string.
-  std::map<std::string, std::unique_ptr<CastSocket::Observer>>
-      socket_observer_map_;
-
-  scoped_refptr<cast_channel::Logger> logger_;
+  scoped_refptr<Logger> logger_;
 
   std::unique_ptr<CastSocket> socket_for_test_;
 
   THREAD_CHECKER(thread_checker_);
 
   DISALLOW_COPY_AND_ASSIGN(CastSocketService);
 };
 
 }  // namespace cast_channel
 
 #endif  // COMPONENTS_CAST_CHANNEL_CAST_CHANNEL_SERVICE_H_