media: Add static MojoCdmService::GetCdm().

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 c669a74b73b9fd3d4f14da7f374ae8b5164c7e6b..7df3df61fd1153a2459695f9a6d787f2fd302797 100644
--- a/media/mojo/services/mojo_cdm_service.h
+++ b/media/mojo/services/mojo_cdm_service.h
@@ -25,6 +25,16 @@ class CdmFactory;
 // media::MediaKeys.
 class MojoCdmService : public interfaces::ContentDecryptionModule {
  public:
+  // Get the CDM associated with |cdm_id|, which is unique per process.
+  // Can be called on any thread. The returned CDM is not guaranteed to be
+  // thread safe.
+  // Note: This provides a generic hack to get the CDM in the process where
+  // MojoMediaApplication is running, regardless of which render process or
+  // render frame the caller is associated with. In the future, we should move
+  // all out-of-process media players into the MojoMediaApplicaiton so that we
+  // can use MojoCdmServiceContext (per render frame) to get the CDM.
+  static scoped_refptr<MediaKeys> GetCdm(int cdm_id);
+
   // Constructs a MojoCdmService and strongly binds it to the |request|.
   MojoCdmService(
       base::WeakPtr<MojoCdmServiceContext> context,