Don't try to create a verbatim match with an empty input.

components/omnibox/browser/verbatim_match.cc

 // Copyright 2015 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/verbatim_match.h"
 
+#include "base/logging.h"
 #include "components/omnibox/browser/autocomplete_classifier.h"
 #include "components/omnibox/browser/autocomplete_input.h"
 #include "components/omnibox/browser/autocomplete_provider_client.h"
 #include "components/omnibox/browser/history_url_provider.h"
 #include "components/search/search.h"
 #include "url/gurl.h"
 
 AutocompleteMatch VerbatimMatchForURL(
     AutocompleteProviderClient* client,
     const AutocompleteInput& input,
     const GURL& destination_url,
     HistoryURLProvider* history_url_provider,
     int verbatim_relevance) {
+  DCHECK(input.text().length());

[sdefresne, 2016/07/05 10:08:56]

nit: I would use DCHECK(!input.text().empty())

[jif, 2016/07/11 15:09:36]

Done.

   AutocompleteMatch match;
   // If query-in-the-omnibox is not enabled (and thus the verbatim match for
   // a URL is guaranteed to be a URL) and the caller already knows where the
   // verbatim match should go and has provided a HistoryURLProvider to aid in
   // its construction, construct the match directly, don't call Classify() on
   // the input.  Classify() runs all providers' synchronous passes.  Some
   // providers such as HistoryQuick can have a slow synchronous pass on some
   // inputs.
   if (history_url_provider && destination_url.is_valid() &&
       !search::IsQueryExtractionEnabled()) {
     match = history_url_provider->SuggestExactInput(
         input,
         destination_url,
         !AutocompleteInput::HasHTTPScheme(input.text()));
   } else {
     client->Classify(input.text(), false, true,
                      input.current_page_classification(), &match, nullptr);
   }
   match.allowed_to_be_default_match = true;
   // The default relevance to use for relevance match. Should be greater than
   // all relevance matches returned by the ZeroSuggest server.
   const int kDefaultVerbatimRelevance = 1300;
   match.relevance =
       verbatim_relevance >= 0 ? verbatim_relevance : kDefaultVerbatimRelevance;
   return match;
 }