Replace further questionable HashMap::add usages in bindings

BUG=390928
R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/411273002

git-svn-id: svn://svn.chromium.org/blink/trunk@178823 bbb929c8-8fbe-4397-9dbb-9b2b20218538
    bool doReadAesKey(blink::WebCryptoKeyAlgorithm& algorithm, blink::WebCryptoKeyType& type)
    {
        blink::WebCryptoAlgorithmId id;
        if (!doReadAlgorithmId(id))
            return false;
        uint32_t lengthBytes;
        if (!doReadUint32(&lengthBytes))
            return false;
        algorithm = blink::WebCryptoKeyAlgorithm::createAes(id, lengthBytes * 8);
        type = blink::WebCryptoKeyTypeSecret;
        return !algorithm.isNull();
    }

    bool doReadAesKey(blink::WebCryptoKeyAlgorithm& algorithm, blink::WebCryptoKeyType& type)
    {
        blink::WebCryptoAlgorithmId id;
        if (!doReadAlgorithmId(id))
            return false;
        uint32_t lengthBytes;
        if (!doReadUint32(&lengthBytes))
            return false;
        algorithm = blink::WebCryptoKeyAlgorithm::createAes(id, lengthBytes * 8);
        type = blink::WebCryptoKeyTypeSecret;
        return !algorithm.isNull();
    }
