Omnibox: Reduce Bolding Flicker in SearchProvider

chrome/browser/autocomplete/search_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.
 //
 // This file contains the Search autocomplete provider.  This provider is
 // responsible for all autocomplete entries that start with "Search <engine>
 // for ...", including searching for the current input string, search
 // history, and search suggestions.  An instance of it gets created and
 // managed by the autocomplete controller.
 
@@ skipping 197 matching lines @@
    public:
     SuggestResult(const base::string16& suggestion,
                   AutocompleteMatchType::Type type,
                   const base::string16& match_contents,
                   const base::string16& annotation,
                   const std::string& suggest_query_params,
                   const std::string& deletion_url,
                   bool from_keyword_provider,
                   int relevance,
                   bool relevance_from_server,
-                  bool should_prefetch);
+                  bool should_prefetch,
+                  const base::string16& input_text);
     virtual ~SuggestResult();
 
     const base::string16& suggestion() const { return suggestion_; }
     AutocompleteMatchType::Type type() const { return type_; }
     const base::string16& match_contents() const { return match_contents_; }
+    const ACMatchClassifications& match_contents_class() const {

[msw, 2014/01/06 21:09:00]

nit: consider match_classifications_ or match_class_

[Mark P, 2014/01/06 22:20:16]

I'd prefer to keep the name that corresponds to the name of the variable name in
the corresponding AutocompleteMatch.

Note that there are two variables of types of ACMatchClassification associated
with an AutocompleteMatch, so referring to something as, say,
match_classification is unclear.

[msw, 2014/01/06 22:50:21]

okay

+      return match_contents_class_;
+    }
     const base::string16& annotation() const { return annotation_; }
     const std::string& suggest_query_params() const {
       return suggest_query_params_;
     }
     const std::string& deletion_url() const { return deletion_url_; }
     bool should_prefetch() const { return should_prefetch_; }
 
+    // Fills in |match_contents_class| to reflect how |match_contents_| should
+    // be displayed and bolded against the current |input_text|.  If
+    // |allow_bolding_all| is false and |match_contents_class_| would have all
+    // of |match_contents_| bolded, do nothing.
+    void CalculateContentsClass(const bool allow_bolding_all,

[msw, 2014/01/06 21:09:00]

nit: consider "Calculate[Match]Classifications".

[Mark P, 2014/01/06 22:20:16]

see comment above.

+                                const base::string16& input_text);
+
     // Result:
     virtual bool IsInlineable(const base::string16& input) const OVERRIDE;
     virtual int CalculateRelevance(
         const AutocompleteInput& input,
         bool keyword_provider_requested) const OVERRIDE;
 
    private:
     // The search terms to be used for this suggestion.
     base::string16 suggestion_;
 
     AutocompleteMatchType::Type type_;
 
-    // The contents to be displayed in the autocomplete match.
+    // The contents to be displayed in the autocomplete match, and its style

[msw, 2014/01/06 21:09:00]

nit: remove "in the autocomplete match"

[Mark P, 2014/01/06 22:20:16]

Done.

+    // info.
     base::string16 match_contents_;
+    ACMatchClassifications match_contents_class_;
 
     // Optional annotation for the |match_contents_| for disambiguation.
     // This may be displayed in the autocomplete match contents, but is defined
     // separately to facilitate different formatting.
     base::string16 annotation_;
 
     // Optional additional parameters to be added to the search URL.
     std::string suggest_query_params_;
 
     // Optional deletion URL provided with suggestions. Fetching this URL
@@ skipping 108 matching lines @@
       int omnibox_start_margin,
       bool append_extra_query_params);
 
   // Removes non-inlineable results until either the top result can inline
   // autocomplete the current input or verbatim outscores the top result.
   static void RemoveStaleResults(const base::string16& input,
                                  int verbatim_relevance,
                                  SuggestResults* suggest_results,
                                  NavigationResults* navigation_results);
 
+  // For every result in |suggest_results|, call CalculateContentsClass(),

[msw, 2014/01/06 21:09:00]

nit: consider "Recalculates the match contents and classifications of
|suggest_results|, given the current input." or similar.

[Mark P, 2014/01/06 22:20:16]

Shortened it much like you suggested.  In the process, dropped the "match
contents" section because I realized this doesn't recalculate match contents. 
(That was an earlier version of this change.)

+  // which may replace its contents and bolding to better display against the
+  // current input.
+  static void RecalculateBolding(const base::string16& input_text,

[msw, 2014/01/06 21:09:00]

nit: consider "Recalculate[Match]Classifications" or similar. Bolding seems like
an implementation detail of the presentation of certain match classifications.

[Mark P, 2014/01/06 22:20:16]

Good point.  Changed to RecalculateMatchContentsClass().

+                                 SuggestResults* suggest_results);
+
   // Calculates the relevance score for the keyword verbatim result (if the
   // input matches one of the profile's keyword).
   static int CalculateRelevanceForKeywordVerbatim(AutocompleteInput::Type type,
                                                   bool prefer_keyword);
 
   // AutocompleteProvider:
   virtual void Start(const AutocompleteInput& input,
                      bool minimal_changes) OVERRIDE;
   virtual void Stop(bool clear_cached_results) OVERRIDE;
 
@@ skipping 280 matching lines @@
   // If true, search history query suggestions will score low enough that
   // they will not be inlined.
   bool prevent_search_history_inlining_;
 
   GURL current_page_url_;
 
   DISALLOW_COPY_AND_ASSIGN(SearchProvider);
 };
 
 #endif  // CHROME_BROWSER_AUTOCOMPLETE_SEARCH_PROVIDER_H_