--- a/dom/media/MediaDecoderStateMachine.h
+++ b/dom/media/MediaDecoderStateMachine.h
@@ -210,19 +210,17 @@ public:
       }
     });
     OwnerThread()->Dispatch(r.forget());
   }
 
   // Drop reference to mReader and mResource. Only called during shutdown dance.
   void BreakCycles() {
     MOZ_ASSERT(NS_IsMainThread());
-    if (mReader) {
-      mReader->BreakCycles();
-    }
+    mReader->BreakCycles();
     mResource = nullptr;
   }
 
   TimedMetadataEventSource& TimedMetadataEvent() {
     return mMetadataManager.TimedMetadataEvent();
   }
 
   MediaEventSource<void>& OnMediaNotSeekable() {
@@ -243,27 +241,21 @@ public:
 
   MediaEventSource<MediaDecoderEventVisibility>&
   OnSeekingStart() { return mOnSeekingStart; }
 
   // Immutable after construction - may be called on any thread.
   bool IsRealTime() const { return mRealTime; }
 
   size_t SizeOfVideoQueue() {
-    if (mReader) {
-      return mReader->SizeOfVideoQueueInBytes();
-    }
-    return 0;
+    return mReader->SizeOfVideoQueueInBytes();
   }
 
   size_t SizeOfAudioQueue() {
-    if (mReader) {
-      return mReader->SizeOfAudioQueueInBytes();
-    }
-    return 0;
+    return mReader->SizeOfAudioQueueInBytes();
   }
 
 private:
   // Functions used by assertions to ensure we're calling things
   // on the appropriate threads.
   bool OnTaskQueue() const;
 
   // Initialization that needs to happen on the task queue. This is the first