Revert of Generating autocomplete results with and without word breaks in the Omnibox.

components/omnibox/browser/url_index_private_data.cc

Index: components/omnibox/browser/url_index_private_data.cc
diff --git a/components/omnibox/browser/url_index_private_data.cc b/components/omnibox/browser/url_index_private_data.cc
index 5e7f99c6cee99578326402f23d3e38fa1bb4d82d..6ca56db8c245fcce787c720aeaa98eb36e788d4b 100644
--- a/components/omnibox/browser/url_index_private_data.cc
+++ b/components/omnibox/browser/url_index_private_data.cc
@@ -81,6 +81,7 @@ bool LengthGreater(const base::string16& string_a,
   return string_a.length() > string_b.length();
 }
 
+
 // UpdateRecentVisitsFromHistoryDBTask -----------------------------------------
 
 // HistoryDBTask used to update the recent visit data for a particular
@@ -157,6 +158,14 @@ ScoredHistoryMatches URLIndexPrivateData::HistoryItemsForTerms(
     size_t max_matches,
     bookmarks::BookmarkModel* bookmark_model,
     TemplateURLService* template_url_service) {
+  // If cursor position is set and useful (not at either end of the
+  // string), allow the search string to be broken at cursor position.
+  // We do this by pretending there's a space where the cursor is.
+  if ((cursor_position != base::string16::npos) &&
+      (cursor_position < search_string.length()) &&
+      (cursor_position > 0)) {
+    search_string.insert(cursor_position, base::ASCIIToUTF16(" "));
+  }
   pre_filter_item_count_ = 0;
   post_filter_item_count_ = 0;
   post_scoring_item_count_ = 0;
@@ -169,7 +178,6 @@ ScoredHistoryMatches URLIndexPrivateData::HistoryItemsForTerms(
       net::UnescapeURLComponent(lower_raw_string,
           net::UnescapeRule::SPACES | net::UnescapeRule::PATH_SEPARATORS |
           net::UnescapeRule::URL_SPECIAL_CHARS_EXCEPT_PATH_SEPARATORS);
-
   // Extract individual 'words' (as opposed to 'terms'; see below) from the
   // search string. When the user types "colspec=ID%20Mstone Release" we get
   // four 'words': "colspec", "id", "mstone" and "release".
@@ -232,7 +240,6 @@ ScoredHistoryMatches URLIndexPrivateData::HistoryItemsForTerms(
   String16Vector lower_raw_terms = base::SplitString(
       lower_raw_string, base::kWhitespaceUTF16, base::KEEP_WHITESPACE,
       base::SPLIT_WANT_NONEMPTY);
-
   if (lower_raw_terms.empty()) {
     // Don't score matches when there are no terms to score against.  (It's
     // possible that the word break iterater that extracts words to search
@@ -243,88 +250,21 @@ ScoredHistoryMatches URLIndexPrivateData::HistoryItemsForTerms(
     // but this is such a rare edge case that it's not worth the time.
     return scored_items;
   }
-
   scored_items =
       std::for_each(
           history_id_set.begin(), history_id_set.end(),
           AddHistoryMatch(bookmark_model, template_url_service, *this,
-                          lower_raw_string, lower_raw_terms, base::Time::Now()))
-          .ScoredMatches();
-
-  // If cursor position is set and useful (not at either end of the string),
-  // allow the search string to be broken at cursor position. We do this by
-  // pretending there's a space where the cursor is.
-  // This phenomena will be referred to as space ghosting.
-  // Going forward we perform a similar process for obtaining
-  // scored items as above.  In fact all of the variable names are the same
-  // except that they are prepended with 'transformed_' reflecting that these
-  // variables are related to space ghosting.
-  if ((cursor_position != base::string16::npos) &&
-      (cursor_position < search_string.length()) && (cursor_position > 0)) {
-    // The original search_string broken at cursor position.
-    base::string16 transformed_search_string(search_string);
-    transformed_search_string.insert(cursor_position, base::ASCIIToUTF16(" "));
-
-    // The same as lower_raw_string and defined for the same reasons.
-    base::string16 transformed_lower_raw_string(
-        base::i18n::ToLower(transformed_search_string));
-    String16Vector transformed_lower_raw_terms =
-        base::SplitString(transformed_lower_raw_string, base::kWhitespaceUTF16,
-                          base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
-    if (!transformed_lower_raw_terms.empty()) {
-      base::string16 transormed_lower_unescaped_string =
-          net::UnescapeURLComponent(
-              transformed_lower_raw_string,
-              net::UnescapeRule::SPACES | net::UnescapeRule::PATH_SEPARATORS |
-                  net::UnescapeRule::URL_SPECIAL_CHARS_EXCEPT_PATH_SEPARATORS);
-      String16Vector transformed_lower_words(String16VectorFromString16(
-          transormed_lower_unescaped_string, false, nullptr));
-      HistoryIDSet transformed_history_id_set =
-          HistoryIDSetFromWords(transformed_lower_words);
-
-      if (history_id_set != transformed_history_id_set) {
-        pre_filter_item_count_ = history_id_set.size();
-        // Trim the candidate pool if it is large as above.
-        was_trimmed = (pre_filter_item_count_ > kItemsToScoreLimit);
-        if (was_trimmed) {
-          HistoryIDVector transformed_history_ids;
-          std::copy(transformed_history_id_set.begin(),
-                    transformed_history_id_set.end(),
-                    std::back_inserter(transformed_history_ids));
-          // Trim down the set by sorting by typed-count, visit-count, and last
-          // visit.
-          HistoryItemFactorGreater item_factor_functor(history_info_map_);
-          std::partial_sort(
-              transformed_history_ids.begin(),
-              transformed_history_ids.begin() + kItemsToScoreLimit,
-              transformed_history_ids.end(), item_factor_functor);
-          transformed_history_id_set.clear();
-          std::copy(transformed_history_ids.begin(),
-                    transformed_history_ids.begin() + kItemsToScoreLimit,
-                    std::inserter(transformed_history_id_set,
-                                  transformed_history_id_set.end()));
-        }
-        history_id_set.insert(transformed_history_id_set.begin(),
-                              transformed_history_id_set.end());
-        ScoredHistoryMatches transformed_scored_items =
-            std::for_each(
-                history_id_set.begin(), history_id_set.end(),
-                AddHistoryMatch(bookmark_model, template_url_service, *this,
-                                transformed_lower_raw_string,
-                                transformed_lower_raw_terms, base::Time::Now()))
-                .ScoredMatches();
-        scored_items.insert(scored_items.end(),
-                            transformed_scored_items.begin(),
-                            transformed_scored_items.end());
-      }
-    }
-  }
+                          lower_raw_string, lower_raw_terms,
+                          base::Time::Now())).ScoredMatches();
+
   // Select and sort only the top |max_matches| results.
   if (scored_items.size() > max_matches) {
-    std::partial_sort(scored_items.begin(), scored_items.begin() + max_matches,
+    std::partial_sort(scored_items.begin(),
+                      scored_items.begin() +
+                          max_matches,
                       scored_items.end(),
                       ScoredHistoryMatch::MatchScoreGreater);
-    scored_items.resize(max_matches);
+      scored_items.resize(max_matches);
   } else {
     std::sort(scored_items.begin(), scored_items.end(),
               ScoredHistoryMatch::MatchScoreGreater);
@@ -1311,6 +1251,7 @@ bool URLIndexPrivateData::URLSchemeIsWhitelisted(
   return whitelist.find(gurl.scheme()) != whitelist.end();
 }
 
+
 // SearchTermCacheItem ---------------------------------------------------------
 
 URLIndexPrivateData::SearchTermCacheItem::SearchTermCacheItem(