[chromecast] Start deprecating MediaMessageLoop.

chromecast/browser/media/cast_browser_cdm_factory.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 CHROMECAST_BROWSER_MEDIA_CAST_BROWSER_CDM_FACTORY_H_
 #define CHROMECAST_BROWSER_MEDIA_CAST_BROWSER_CDM_FACTORY_H_
 
 #include "base/macros.h"
 #include "chromecast/media/base/key_systems_common.h"
 #include "media/base/cdm_factory.h"
 #include "media/base/media_keys.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}  // namespace base
+
 namespace chromecast {
 namespace media {
 
 class BrowserCdmCast;
 
 class CastBrowserCdmFactory : public ::media::CdmFactory {
  public:
-  CastBrowserCdmFactory() {}
-  ~CastBrowserCdmFactory() override {};
+  // CDM factory will use |task_runner| to initialize the CDM.
+  explicit CastBrowserCdmFactory(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+  ~CastBrowserCdmFactory() override;
 
   // ::media::CdmFactory implementation:
   void Create(
       const std::string& key_system,
       const GURL& security_origin,
       const ::media::CdmConfig& cdm_config,
       const ::media::SessionMessageCB& session_message_cb,
       const ::media::SessionClosedCB& session_closed_cb,
       const ::media::LegacySessionErrorCB& legacy_session_error_cb,
       const ::media::SessionKeysChangeCB& session_keys_change_cb,
       const ::media::SessionExpirationUpdateCB& session_expiration_update_cb,
       const ::media::CdmCreatedCB& cdm_created_cb) override;
 
   // Provides a platform-specific BrowserCdm instance.
   virtual scoped_refptr<BrowserCdmCast> CreatePlatformBrowserCdm(
       const CastKeySystem& cast_key_system);
 
  private:
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   DISALLOW_COPY_AND_ASSIGN(CastBrowserCdmFactory);
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_BROWSER_MEDIA_CAST_BROWSER_CDM_FACTORY_H_