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

components/autofill/core/browser/personal_data_manager.h

 // 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.
 
 #ifndef COMPONENTS_AUTOFILL_CORE_BROWSER_PERSONAL_DATA_MANAGER_H_
 #define COMPONENTS_AUTOFILL_CORE_BROWSER_PERSONAL_DATA_MANAGER_H_
 
 #include <memory>
 #include <set>
 #include <vector>
@@ skipping 198 matching lines @@
   // Checks suitability of |profile| for adding to the user's set of profiles.
   static bool IsValidLearnableProfile(const AutofillProfile& profile,
                                       const std::string& app_locale);
 
   // Merges |new_profile| into one of the |existing_profiles| if possible;
   // otherwise appends |new_profile| to the end of that list. Fills
   // |merged_profiles| with the result. Returns the |guid| of the new or updated
   // profile.
   static std::string 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);
 
   // Returns true if |country_code| is a country that the user is likely to
   // be associated with the user. More concretely, it checks if there are any
   // addresses with this country or if the user's system timezone is in the
   // given country.
   virtual bool IsCountryOfInterest(const std::string& country_code) const;
 
   // Returns our best guess for the country a user is likely to use when
@@ skipping 198 matching lines @@
 
   // An observer to listen for changes to prefs::kAutofillWalletImportEnabled.
   std::unique_ptr<BooleanPrefMember> wallet_enabled_pref_;
 
   DISALLOW_COPY_AND_ASSIGN(PersonalDataManager);
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_CORE_BROWSER_PERSONAL_DATA_MANAGER_H_