[cast_channel] Create KeepAliveDelegate in CastSocket instead of in CastChannelOpenFunction

extensions/browser/api/cast_channel/cast_channel_api.h

 // Copyright 2014 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 EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_CHANNEL_API_H_
 #define EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_CHANNEL_API_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 47 matching lines @@
   void SetSocketForTest(
       std::unique_ptr<cast_channel::CastSocket> socket_for_test);
 
   // Returns a test CastSocket instance, if it is defined.
   // Otherwise returns a scoped_ptr with a nullptr value.
   std::unique_ptr<cast_channel::CastSocket> GetSocketForTest();
 
   // Returns the API browser context.
   content::BrowserContext* GetBrowserContext() const;
 
-  // Sets injected ping timeout timer for testing.
-  void SetPingTimeoutTimerForTest(std::unique_ptr<base::Timer> timer);
-
-  // Gets the injected ping timeout timer, if set.
-  // Returns a null scoped ptr if there is no injected timer.
-  std::unique_ptr<base::Timer> GetInjectedTimeoutTimerForTest();
-
   // Sends an event to the extension's EventRouter, if it exists.
   void SendEvent(const std::string& extension_id, std::unique_ptr<Event> event);
 
  private:
   friend class BrowserContextKeyedAPIFactory<CastChannelAPI>;
   friend class ::CastChannelAPITest;
   friend class CastTransportDelegate;
 
   ~CastChannelAPI() override;
 
   // BrowserContextKeyedAPI implementation.
   static const char* service_name() { return "CastChannelAPI"; }
 
   content::BrowserContext* const browser_context_;
   scoped_refptr<cast_channel::Logger> logger_;
   std::unique_ptr<cast_channel::CastSocket> socket_for_test_;
-  std::unique_ptr<base::Timer> injected_timeout_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(CastChannelAPI);
 };
 
 class CastChannelAsyncApiFunction : public AsyncApiFunction {
  public:
   CastChannelAsyncApiFunction();
 
  protected:
   ~CastChannelAsyncApiFunction() override;
@@ skipping 125 matching lines @@
 
   std::unique_ptr<api::cast_channel::Close::Params> params_;
   CastChannelAPI* api_;
 
   DISALLOW_COPY_AND_ASSIGN(CastChannelCloseFunction);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_CHANNEL_API_H_