[Autofill] Sort existing profiles by frecency before trying to merge.

components/autofill/core/browser/personal_data_manager.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/personal_data_manager.h"
 
 #include <stddef.h>
 #include <algorithm>
 #include <list>
 #include <map>
@@ skipping 848 matching lines @@
   // Reject profiles with invalid US zip information.
   if (profile.IsPresentButInvalid(ADDRESS_HOME_ZIP))
     return false;
 
   return true;
 }
 
 // static
 std::string PersonalDataManager::MergeProfile(
     const AutofillProfile& new_profile,
-    const std::vector<AutofillProfile*>& existing_profiles,
+    std::vector<AutofillProfile*> existing_profiles,
     const std::string& app_locale,
     std::vector<AutofillProfile>* merged_profiles) {
   merged_profiles->clear();
 
+  // Sort the existing profiles in decreasing order of frecency, so the "best"
+  // profiles are checked first.
+  base::Time comparison_time = base::Time::Now();
+  std::sort(existing_profiles.begin(), existing_profiles.end(),
+            [comparison_time](const AutofillDataModel* a,
+                              const AutofillDataModel* b) {
+              return a->CompareFrecency(b, comparison_time);
+            });
+
   // Set to true if |existing_profiles| already contains an equivalent profile.
   bool matching_profile_found = false;
   std::string guid = new_profile.guid();
 
   // If we have already saved this address, merge in any missing values.
   // Only merge with the first match.
   for (AutofillProfile* existing_profile : existing_profiles) {
     if (!matching_profile_found && !new_profile.PrimaryValue().empty() &&
         existing_profile->SaveAdditionalInfo(new_profile, app_locale)) {
       // Unverified profiles should always be updated with the newer data,
@@ skipping 615 matching lines @@
     std::stable_sort(suggestions.begin(), suggestions.end(),
                      [](const Suggestion& a, const Suggestion& b) {
                        return a.match < b.match;
                      });
   }
 
   return suggestions;
 }
 
 }  // namespace autofill