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

media/mojo/services/mojo_renderer_impl.cc

Index: media/mojo/services/mojo_renderer_impl.cc
diff --git a/media/mojo/services/mojo_renderer_impl.cc b/media/mojo/services/mojo_renderer_impl.cc
index 482e73b16a1fb7a50d4da7aa2b8ce7b55d85d2d9..56ee78ed6bf42e8bbea4a1649648bf5084eefa84 100644
--- a/media/mojo/services/mojo_renderer_impl.cc
+++ b/media/mojo/services/mojo_renderer_impl.cc
@@ -84,8 +84,14 @@ void MojoRendererImpl::SetCdm(CdmContext* cdm_context,
                               const CdmAttachedCB& cdm_attached_cb) {
   DVLOG(1) << __FUNCTION__;
   DCHECK(task_runner_->BelongsToCurrentThread());
-  NOTIMPLEMENTED();
-  cdm_attached_cb.Run(false);
+
+  int32_t cdm_id = cdm_context->GetCdmId();
+  if (cdm_id == CdmContext::kInvalidCdmId) {
+    cdm_attached_cb.Run(false);
+    return;
+  }
+
+  remote_media_renderer_->SetCdm(cdm_id, cdm_attached_cb);
 }
 
 void MojoRendererImpl::Flush(const base::Closure& flush_cb) {