Omnibox UI Experiments: Add flag to change max autocomplete matches.

components/omnibox/browser/search_provider.cc

 // Copyright 2012 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/search_provider.h"
 
 #include <stddef.h>
 #include <algorithm>
 #include <cmath>
 #include <utility>
@@ skipping 1027 matching lines @@
     matches.push_back(i->second);
 
   AddNavigationResultsToMatches(keyword_results_.navigation_results, &matches);
   AddNavigationResultsToMatches(default_results_.navigation_results, &matches);
 
   // Now add the most relevant matches to |matches_|.  We take up to kMaxMatches
   // suggest/navsuggest matches, regardless of origin.  We always include in
   // that set a legal default match if possible.  If Instant Extended is enabled
   // and we have server-provided (and thus hopefully more accurate) scores for
   // some suggestions, we allow more of those, until we reach
-  // AutocompleteResult::kMaxMatches total matches (that is, enough to fill the
-  // whole popup).
+  // AutocompleteResult::GetMaxMatches() total matches (that is, enough to fill
+  // the whole popup).
   //
   // We will always return any verbatim matches, no matter how we obtained their
-  // scores, unless we have already accepted AutocompleteResult::kMaxMatches
+  // scores, unless we have already accepted AutocompleteResult::GetMaxMatches()
   // higher-scoring matches under the conditions above.
   std::sort(matches.begin(), matches.end(), &AutocompleteMatch::MoreRelevant);
 
   // Guarantee that if there's a legal default match anywhere in the result
   // set that it'll get returned.  The rotate() call does this by moving the
   // default match to the front of the list.
   ACMatches::iterator default_match =
       AutocompleteResult::FindTopMatch(&matches);
   if (default_match != matches.end())
     std::rotate(matches.begin(), default_match, default_match + 1);
 
   // It's possible to get a copy of an answer from previous matches and get the
   // same or a different answer to another server-provided suggestion.  In the
   // future we may decide that we want to have answers attached to multiple
   // suggestions, but the current assumption is that there should only ever be
   // one suggestion with an answer.  To maintain this assumption, remove any
   // answers after the first.
   RemoveExtraAnswers(&matches);
 
   matches_.clear();
   size_t num_suggestions = 0;
   for (ACMatches::const_iterator i(matches.begin());
        (i != matches.end()) &&
-           (matches_.size() < AutocompleteResult::kMaxMatches);
+       (matches_.size() < AutocompleteResult::GetMaxMatches());
        ++i) {
     // SEARCH_OTHER_ENGINE is only used in the SearchProvider for the keyword
     // verbatim result, so this condition basically means "if this match is a
     // suggestion of some sort".
     if ((i->type != AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED) &&
         (i->type != AutocompleteMatchType::SEARCH_OTHER_ENGINE)) {
       // If we've already hit the limit on non-server-scored suggestions, and
       // this isn't a server-scored suggestion we can add, skip it.
       if ((num_suggestions >= kMaxMatches) &&
           (!search::IsInstantExtendedAPIEnabled() ||
@@ skipping 458 matching lines @@
   for (MatchMap::const_iterator i(map.begin()); i != map.end(); ++i)
     matches.push_back(i->second);
   std::sort(matches.begin(), matches.end(), &AutocompleteMatch::MoreRelevant);
 
   // If there is a top scoring entry, find the corresponding answer.
   if (!matches.empty())
     return answers_cache_.GetTopAnswerEntry(matches[0].contents);
 
   return AnswersQueryData();
 }