media: Reject pending CDM promise during destruction.

media/blink/new_session_cdm_result_promise.cc

Index: media/blink/new_session_cdm_result_promise.cc
diff --git a/media/blink/new_session_cdm_result_promise.cc b/media/blink/new_session_cdm_result_promise.cc
index 4a97c34720894641b932b94b35bff19ace670e2d..88268623102e34c2f70541a700b709102d1ee216 100644
--- a/media/blink/new_session_cdm_result_promise.cc
+++ b/media/blink/new_session_cdm_result_promise.cc
@@ -36,6 +36,11 @@ NewSessionCdmResultPromise::NewSessionCdmResultPromise(
 }
 
 NewSessionCdmResultPromise::~NewSessionCdmResultPromise() {
+  if (IsPromiseSettled())
+    return;
+
+  DCHECK(!web_cdm_result_.isCompleted());
+  RejectPromiseOnDestruction();
 }
 
 void NewSessionCdmResultPromise::resolve(const std::string& session_id) {