Omnibox: Add Field Trial to Create UWYT When Inlining

chrome/browser/autocomplete/history_url_provider.h

 // Copyright (c) 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.
 
 #ifndef CHROME_BROWSER_AUTOCOMPLETE_HISTORY_URL_PROVIDER_H_
 #define CHROME_BROWSER_AUTOCOMPLETE_HISTORY_URL_PROVIDER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 227 matching lines @@
 
   // Actually runs the autocomplete job on the given database, which is
   // guaranteed not to be NULL.  Used by both autocomplete passes, and therefore
   // called on multiple different threads (though not simultaneously).
   void DoAutocomplete(history::HistoryBackend* backend,
                       history::URLDatabase* db,
                       HistoryURLProviderParams* params);
 
   // May promote either the what you typed match or first history match in
   // params->matches to the front of |matches_|, depending on the value of
-  // params->promote_type.
-  void PromoteMatchIfNecessary(const HistoryURLProviderParams& params);
+  // params->promote_type.  Also, depending on a field trial state, if it
+  // promotes the first history match, it may decide to append the what you
+  // typed matche immediately after.
+  void PromoteMatchesIfNecessary(const HistoryURLProviderParams& params);
 
   // Dispatches the results to the autocomplete controller. Called on the
   // main thread by ExecuteWithDB when the results are available.
   // Frees params_gets_deleted on exit.
   void QueryComplete(HistoryURLProviderParams* params_gets_deleted);
 
+  // Returns whether we should consider showing the what you typed match.
+  static bool HaveWhatYouTypedMatch(const VisitClassifier& classifier,
+                                    const HistoryURLProviderParams& params);
+
   // Looks up the info for params->what_you_typed_match in the DB.  If found,
   // fills in the title, promotes the match's priority to that of an inline
   // autocomplete match (maybe it should be slightly better?), and places it on
   // the front of params->matches (so we pick the right matches to throw away
   // when culling redirects to/from it).  Returns whether a match was promoted.
   bool FixupExactSuggestion(history::URLDatabase* db,
                             const VisitClassifier& classifier,
                             HistoryURLProviderParams* params) const;
 
   // Helper function for FixupExactSuggestion, this returns true if the input
@@ skipping 70 matching lines @@
   // Used in PromoteOrCreateShorterSuggestion().  If true, we may create
   // shorter suggestions even when they haven't been visited before:
   // if the user visited http://example.com/asdf once, we'll suggest
   // http://example.com/ even if they've never been to it.
   bool create_shorter_match_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryURLProvider);
 };
 
 #endif  // CHROME_BROWSER_AUTOCOMPLETE_HISTORY_URL_PROVIDER_H_