Bug 1400019 - Don't assert on illegal WebAuthn algo names r=keeler

The algorithm names provided to the WebAuthn methods have to either be a
string, or (potentially) a WebCrypto object. Right now we only work with
strings, but there's no good reason to assert that, we can just let the
action fail.

This patch removes the assert to help out the fuzzing team.

MozReview-Commit-ID: 9dc8m0a2gZK

--HG--
extra : rebase_source : 649a7f4928679405fe445ac533eee2cfccaedd25

dom/webauthn/WebAuthnManager.cpp

@@ -56,8 +56,6 @@ static nsresult
 GetAlgorithmName(const OOS& aAlgorithm,
                  /* out */ nsString& aName)
 {
-  MOZ_ASSERT(aAlgorithm.IsString()); // TODO: remove assertion when we coerce.
-
   if (aAlgorithm.IsString()) {
     // If string, then treat as algorithm name
     aName.Assign(aAlgorithm.GetAsString());