Mark URLs with empty schemes as invalid.

components/omnibox/browser/autocomplete_input.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/omnibox/browser/autocomplete_input.h"
 
 #include "base/macros.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 236 matching lines @@
     // the option of treating it as a URL if we're wrong.
     // Note that SegmentURL() is smart so we aren't tricked by "c:\foo" or
     // "www.example.com:81" in this case.
     return metrics::OmniboxInputType::UNKNOWN;
   }
 
   // Either the user didn't type a scheme, in which case we need to distinguish
   // 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
   // IPv4 address but with a non-empty desired TLD would return IPV4 before
   // fixup and NEUTRAL afterwards, and we want to treat it as NEUTRAL).
   url::CanonHostInfo host_info;
   net::CanonicalizeHost(canonicalized_url->host(), &host_info);
 
   // Check if the canonicalized host has a known TLD, which we'll want to know
   // below.
@@ skipping 252 matching lines @@
   parts_ = url::Parsed();
   scheme_.clear();
   canonicalized_url_ = GURL();
   prevent_inline_autocomplete_ = false;
   prefer_keyword_ = false;
   allow_exact_keyword_match_ = false;
   want_asynchronous_matches_ = true;
   from_omnibox_focus_ = false;
   terms_prefixed_by_http_or_https_.clear();
 }