Keep reference to CDM to avoid it's premature destruction

media/blink/webcontentdecryptionmodule_impl.cc

Index: media/blink/webcontentdecryptionmodule_impl.cc
diff --git a/media/blink/webcontentdecryptionmodule_impl.cc b/media/blink/webcontentdecryptionmodule_impl.cc
index b54ebe2e8c0da6808004f6fc20017285bc5e2dcc..733c3650aa2c68a116ba4fbb6cdbb3479649386e 100644
--- a/media/blink/webcontentdecryptionmodule_impl.cc
+++ b/media/blink/webcontentdecryptionmodule_impl.cc
@@ -105,4 +105,8 @@ CdmContext* WebContentDecryptionModuleImpl::GetCdmContext() {
   return adapter_->GetCdmContext();
 }
 
+CdmSessionAdapter* WebContentDecryptionModuleImpl::GetCdmAdapterReference() {
+  return adapter_.get();
+}
+
 }  // namespace media