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..57de08c9d0a963a67fb2e409a5bfae54c7e3fe6e 100644
--- a/media/blink/new_session_cdm_result_promise.cc
+++ b/media/blink/new_session_cdm_result_promise.cc
@@ -36,6 +36,13 @@ NewSessionCdmResultPromise::NewSessionCdmResultPromise(
 }
 
 NewSessionCdmResultPromise::~NewSessionCdmResultPromise() {
+  if (web_cdm_result_.isCompleted())
+    return;
+
+  std::string message =
+      "Unfulfilled promise rejected automatically during destruction.";
+  DVLOG(1) << message;
+  reject(MediaKeys::INVALID_STATE_ERROR, 0, message);
 }
 
 void NewSessionCdmResultPromise::resolve(const std::string& session_id) {