Mark URLs with empty schemes as invalid.

components/omnibox/browser/autocomplete_input.cc

Index: components/omnibox/browser/autocomplete_input.cc
diff --git a/components/omnibox/browser/autocomplete_input.cc b/components/omnibox/browser/autocomplete_input.cc
index 7207fc8b5e68ba44e4e354bbc79b4f3317e4d5d1..26a8c7d0f34a1bb70d358f02d0ee768a68f2cf83 100644
--- a/components/omnibox/browser/autocomplete_input.cc
+++ b/components/omnibox/browser/autocomplete_input.cc
@@ -254,13 +254,6 @@ metrics::OmniboxInputType::Type AutocompleteInput::Parse(
   // between an HTTP URL and a query, or the scheme is HTTP or HTTPS, in which
   // case we should reject invalid formulations.
 
-  // If we have an empty host it can't be a valid HTTP[S] URL.  (This should
-  // only trigger for input that begins with a colon, which GURL will parse as a
-  // valid, non-standard URL; for standard URLs, an empty host would have
-  // resulted in an invalid |canonicalized_url| above.)
-  if (!canonicalized_url->has_host())
-    return metrics::OmniboxInputType::QUERY;
-
   // Determine the host family.  We get this information by (re-)canonicalizing
   // the already-canonicalized host rather than using the user's original input,
   // in case fixup affected the result here (e.g. an input that looks like an