Bug 1626787 - ClearKeyDecryptionManager.cpp check emptiness by empty instead of by size. r=sylvestre

Emptiness of values should be checked using the `empty` method, and not
by comparing the size to 0. Fix such case in the code of
ClearKeyDecryptionManager.cpp module.

Differential Revision: https://phabricator.services.mozilla.com/D70206

--HG--
extra : moz-landing-system : lando

media/gmp-clearkey/0.1/ClearKeyDecryptionManager.cpp

@@ -258,7 +258,7 @@ Status ClearKeyDecryptor::Decrypt(uint8_t* aBuffer, uint32_t aBufferSize,
   // encrypted sample lengths are zero, and in this case, a zero length
   // IV is allowed.
   assert(aMetadata.mIV.size() == 8 || aMetadata.mIV.size() == 16 ||
-         (aMetadata.mIV.size() == 0 && AllZero(aMetadata.mCipherBytes)));
+         (aMetadata.mIV.empty() && AllZero(aMetadata.mCipherBytes)));
 
   std::vector<uint8_t> iv(aMetadata.mIV);
   iv.insert(iv.end(), CENC_KEY_LEN - aMetadata.mIV.size(), 0);