[Autofill] Deduplicate Autocomplete and Datalist suggestions, keeping the latter

components/autofill/core/browser/autofill_external_delegate.cc

 // Copyright 2013 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/autofill/core/browser/autofill_external_delegate.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/i18n/case_conversion.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/sparse_histogram.h"
+#include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/autofill/core/browser/autocomplete_history_manager.h"
 #include "components/autofill/core/browser/autofill_driver.h"
 #include "components/autofill/core/browser/autofill_manager.h"
 #include "components/autofill/core/browser/autofill_metrics.h"
 #include "components/autofill/core/browser/popup_item_ids.h"
 #include "components/autofill/core/common/autofill_util.h"
 #include "grit/components_strings.h"
 #include "ui/base/l10n/l10n_util.h"
@@ skipping 279 matching lines @@
   suggestions->back().frontend_id = POPUP_ITEM_ID_AUTOFILL_OPTIONS;
   if (IsKeyboardAccessoryEnabled())
     suggestions->back().icon = base::ASCIIToUTF16("settings");
 }
 
 void AutofillExternalDelegate::InsertDataListValues(
     std::vector<Suggestion>* suggestions) {
   if (data_list_values_.empty())
     return;
 
+  // Go through the list of autocomplete values and remove them if they are in
+  // the list of datalist values.
+  std::set<base::string16> data_list_set(data_list_values_.begin(),
+                                         data_list_values_.end());
+  suggestions->erase(
+      std::remove_if(suggestions->begin(), suggestions->end(),
+                     [&data_list_set](const Suggestion& suggestion) {
+                       return ContainsKey(data_list_set, suggestion.value) &&
+                              suggestion.frontend_id ==
+                                  POPUP_ITEM_ID_AUTOCOMPLETE_ENTRY;

[Evan Stade, 2015/11/19 16:40:10]

nit: i'd reverse the order of these checks since the second one is less
expensive

[Mathieu, 2015/11/19 17:06:21]

Done.

+                     }),
+      suggestions->end());
+
 #if !defined(OS_ANDROID)
-  // Insert the separator between the datalist and Autofill values (if there
-  // are any).
+  // Insert the separator between the datalist and Autofill/Autocomplete values
+  // (if there are any).
   if (!suggestions->empty()) {
     suggestions->insert(suggestions->begin(), Suggestion());
     (*suggestions)[0].frontend_id = POPUP_ITEM_ID_SEPARATOR;
   }
 #endif
 
   // Insert the datalist elements at the beginning.
   suggestions->insert(suggestions->begin(), data_list_values_.size(),
                       Suggestion());
   for (size_t i = 0; i < data_list_values_.size(); i++) {
     (*suggestions)[i].value = data_list_values_[i];
     (*suggestions)[i].label = data_list_labels_[i];
     (*suggestions)[i].frontend_id = POPUP_ITEM_ID_DATALIST_ENTRY;
   }
 }
 
 }  // namespace autofill