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

media/mojo/services/mojo_cdm.h

Index: media/mojo/services/mojo_cdm.h
diff --git a/media/mojo/services/mojo_cdm.h b/media/mojo/services/mojo_cdm.h
index cd7c76c2802311443f5a8a7d2c34a76359c213c7..e9f9d509cc467e03f2c1d68285a72f561066dead 100644
--- a/media/mojo/services/mojo_cdm.h
+++ b/media/mojo/services/mojo_cdm.h
@@ -7,6 +7,7 @@
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "media/base/cdm_context.h"
 #include "media/base/media_keys.h"
 #include "media/mojo/interfaces/content_decryption_module.mojom.h"
 #include "media/mojo/services/mojo_type_trait.h"
@@ -20,11 +21,14 @@ namespace media {
 // A MediaKeys that proxies to a mojo::ContentDecryptionModule. That
 // mojo::ContentDecryptionModule proxies back to the MojoCdm via the
 // mojo::ContentDecryptionModuleClient interface.
-class MojoCdm : public MediaKeys, public mojo::ContentDecryptionModuleClient {
+class MojoCdm : public MediaKeys,
+                public CdmContext,
+                public mojo::ContentDecryptionModuleClient {
  public:
   // |media_renderer_provider| is a ServiceProvider from a connected
   //     Application that is hosting a mojo::MediaRenderer.
   MojoCdm(mojo::ContentDecryptionModulePtr remote_cdm,
+          int32_t cdm_id,
           const SessionMessageCB& session_message_cb,
           const SessionClosedCB& session_closed_cb,
           const SessionErrorCB& session_error_cb,
@@ -55,6 +59,10 @@ class MojoCdm : public MediaKeys, public mojo::ContentDecryptionModuleClient {
                      scoped_ptr<SimpleCdmPromise> promise) final;
   CdmContext* GetCdmContext() final;

[ddorwin, 2015/05/15 19:10:07]

Is there a need to get this as a CdmContext pointer? The public definition
inherits from CdmContext, so it's clear that the returned value should be
"this". Do we even need this method?

 
+  // CdmContext implementation.
+  media::Decryptor* GetDecryptor() final;
+  int GetCdmId() const final;
+
  private:
   // mojo::ContentDecryptionModuleClient implementation.
   void OnSessionMessage(const mojo::String& session_id,
@@ -90,6 +98,8 @@ class MojoCdm : public MediaKeys, public mojo::ContentDecryptionModuleClient {
   mojo::ContentDecryptionModulePtr remote_cdm_;
   mojo::Binding<ContentDecryptionModuleClient> binding_;
 
+  const int32_t cdm_id_;
+
   // Callbacks for firing session events.
   SessionMessageCB session_message_cb_;
   SessionClosedCB session_closed_cb_;