media: Cancel MediaCryptoReadyCB during player destruction.

media/base/android/media_source_player.cc

Index: media/base/android/media_source_player.cc
diff --git a/media/base/android/media_source_player.cc b/media/base/android/media_source_player.cc
index 84c0b43bec05179a924d62abf943deeb89142e95..133e5f71c6c8def3e7ce0ab52758807baf055929 100644
--- a/media/base/android/media_source_player.cc
+++ b/media/base/android/media_source_player.cc
@@ -74,6 +74,10 @@ MediaSourcePlayer::~MediaSourcePlayer() {
   Release();
   DCHECK_EQ(!cdm_, !cdm_registration_id_);
   if (cdm_) {
+    // Cancel previously registered callback (if any).
+    static_cast<MediaDrmBridge*>(cdm_.get())
+        ->SetMediaCryptoReadyCB(MediaDrmBridge::MediaCryptoReadyCB());
+
     static_cast<MediaDrmBridge*>(cdm_.get())
         ->UnregisterPlayer(cdm_registration_id_);
     cdm_registration_id_ = 0;