--- a/dom/media/MediaManager.cpp
+++ b/dom/media/MediaManager.cpp
@@ -1472,28 +1472,23 @@ public:
         }
         if (mAudioDevice) {
           mAudioDevice->Deallocate();
         }
       }
     }
     if (errorMsg) {
       LOG(("%s %d", errorMsg, rv));
-      switch (rv) {
-        case NS_ERROR_NOT_AVAILABLE: {
-          MOZ_ASSERT(badConstraint);
-          Fail(NS_LITERAL_STRING("OverconstrainedError"),
-               NS_LITERAL_STRING(""),
-               NS_ConvertUTF8toUTF16(badConstraint));
-          break;
-        }
-        default:
-          Fail(NS_LITERAL_STRING("NotReadableError"),
-               NS_ConvertUTF8toUTF16(errorMsg));
-          break;
+      if (badConstraint) {
+        Fail(NS_LITERAL_STRING("OverconstrainedError"),
+             NS_LITERAL_STRING(""),
+             NS_ConvertUTF8toUTF16(badConstraint));
+      } else {
+        Fail(NS_LITERAL_STRING("NotReadableError"),
+             NS_ConvertUTF8toUTF16(errorMsg));
       }
       return NS_OK;
     }
     PeerIdentity* peerIdentity = nullptr;
     if (!mConstraints.mPeerIdentity.IsEmpty()) {
       peerIdentity = new PeerIdentity(mConstraints.mPeerIdentity);
     }