new URL('') should throw TypeError

url/url_canon_relative.cc

Index: url/url_canon_relative.cc
diff --git a/url/url_canon_relative.cc b/url/url_canon_relative.cc
index c2e94e418529dd6cde73f2c6a92c225405eb4150..e34ea2fa2495dc6acbb301644dca4b04b3738762 100644
--- a/url/url_canon_relative.cc
+++ b/url/url_canon_relative.cc
@@ -75,6 +75,10 @@ bool DoIsRelativeURL(const char* base,
   TrimURL(url, &begin, &url_len);
   if (begin >= url_len) {
     // Empty URLs are relative, but do nothing.
+    if (!is_base_hierarchical) {
+      // Don't allow relative URLs if the base scheme doesn't support it.
+      return false;
+    }
     *relative_component = Component(begin, 0);
     *is_relative = true;
     return true;