media: Support creation and SetCdm() for mojo based CDM.

media/mojo/services/mojo_cdm_service.h

Index: media/mojo/services/mojo_cdm_service.h
diff --git a/media/mojo/services/mojo_cdm_service.h b/media/mojo/services/mojo_cdm_service.h
index 29e5c1c902236b66345c3ab86858c13186fb691b..46d05bbcc6865abe4f0c0221bea0ab6a9fd65b03 100644
--- a/media/mojo/services/mojo_cdm_service.h
+++ b/media/mojo/services/mojo_cdm_service.h
@@ -15,11 +15,17 @@
 
 namespace media {
 
+class MojoCdmServiceContext;
+
 // A mojo::ContentDecryptionModule implementation backed by a media::MediaKeys.
 class MojoCdmService
     : public mojo::InterfaceImpl<mojo::ContentDecryptionModule> {
  public:
-  MojoCdmService(const mojo::String& key_system);
+  // Creates MojoCdmService for |key_system|. Returns nullptr if |key_system| is
+  // not supported.
+  static MojoCdmService* Create(MojoCdmServiceContext* context,
+                                const mojo::String& key_system);
+
   ~MojoCdmService() final;
 
   // mojo::ContentDecryptionModule implementation.
@@ -47,10 +53,18 @@ class MojoCdmService
   void RemoveSession(
       const mojo::String& session_id,
       const mojo::Callback<void(mojo::CdmPromiseResultPtr)>& callback) final;
-  void GetCdmContext(int32_t cdm_id,
-                     mojo::InterfaceRequest<mojo::Decryptor> decryptor) final;
+  void GetDecryptor(mojo::InterfaceRequest<mojo::Decryptor> decryptor) final;
+
+  // Get CdmContext to be used by the media pipeline.
+  CdmContext* GetCdmContext();
 
  private:
+  MojoCdmService(MojoCdmServiceContext* context,
+                 const mojo::String& key_system);
+
+  // mojo::InterfaceImpl implementation.
+  void OnConnectionError() override;
+
   // Callbacks for firing session events.
   void OnSessionMessage(const std::string& session_id,
                         MediaKeys::MessageType message_type,
@@ -67,6 +81,7 @@ class MojoCdmService
                       uint32_t system_code,
                       const std::string& error_message);
 
+  MojoCdmServiceContext* context_;
   scoped_ptr<MediaKeys> cdm_;
 
   mojo::ContentDecryptionModuleClientPtr client_;