Set callback interface on WebCDMSessionImpl after creation.

content/renderer/media/webcontentdecryptionmodule_impl.cc

Index: content/renderer/media/webcontentdecryptionmodule_impl.cc
diff --git a/content/renderer/media/webcontentdecryptionmodule_impl.cc b/content/renderer/media/webcontentdecryptionmodule_impl.cc
index c1e455e56fe38e08f82bfa1f37a0b5f571a17610..9dcb39ee9ca98931c5f49c05035f805ed883e846 100644
--- a/content/renderer/media/webcontentdecryptionmodule_impl.cc
+++ b/content/renderer/media/webcontentdecryptionmodule_impl.cc
@@ -85,9 +85,16 @@ WebContentDecryptionModuleImpl::~WebContentDecryptionModuleImpl() {
 
 // The caller owns the created session.
 blink::WebContentDecryptionModuleSession*
+WebContentDecryptionModuleImpl::createSession() {
+  return adapter_->CreateSession();
+}
+
+blink::WebContentDecryptionModuleSession*
 WebContentDecryptionModuleImpl::createSession(
     blink::WebContentDecryptionModuleSession::Client* client) {
-  return adapter_->CreateSession(client);
+  WebContentDecryptionModuleSessionImpl* session = adapter_->CreateSession();
+  session->setClientInterface(client);
+  return session;
 }
 
 media::Decryptor* WebContentDecryptionModuleImpl::GetDecryptor() {