Change uses of base::JoinString to pass StringPieces where possible.

components/autofill/core/browser/autofill_profile_comparator.cc

 // Copyright 2016 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_profile_comparator.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/i18n/case_conversion.h"
 #include "base/i18n/char_iterator.h"
-#include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversion_utils.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/autofill/core/browser/address_rewriter.h"
 #include "components/autofill/core/browser/autofill_country.h"
 #include "components/autofill/core/browser/autofill_data_util.h"
 #include "components/autofill/core/browser/state_names.h"
 #include "third_party/libphonenumber/phonenumber_api.h"
 
@@ skipping 637 matching lines @@
   if (!s1.empty())
     return s1;
   return p2.GetInfo(t, app_locale_);
 }
 
 // static
 std::set<base::string16> AutofillProfileComparator::GetNamePartVariants(
     const base::string16& name_part) {
   const size_t kMaxSupportedSubNames = 8;
 
-  std::vector<base::string16> sub_names = base::SplitString(
+  std::vector<base::StringPiece16> sub_names = base::SplitStringPiece(
       name_part, kSpace, base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
 
   // Limit the number of sub-names we support (to constrain memory usage);
   if (sub_names.size() > kMaxSupportedSubNames)
     return {name_part};
 
   // Start with the empty string as a variant.
   std::set<base::string16> variants = {base::EmptyString16()};
 
   // For each sub-name, add a variant of all the already existing variants that
   // appends this sub-name and one that appends the initial of this sub-name.
   // Duplicates will be discarded when they're added to the variants set.
-  for (const base::string16& sub_name : sub_names) {
+  for (auto sub_name : sub_names) {
     if (sub_name.empty())
       continue;
     std::vector<base::string16> new_variants;
     for (const base::string16& variant : variants) {
       new_variants.push_back(base::CollapseWhitespace(
           base::JoinString({variant, sub_name}, kSpace), true));
       new_variants.push_back(base::CollapseWhitespace(
           base::JoinString({variant, sub_name.substr(0, 1)}, kSpace), true));
     }
     variants.insert(new_variants.begin(), new_variants.end());
   }
 
   // As a common case, also add the variant that just concatenates all of the
   // initials.
   base::string16 initials;
-  for (const base::string16& sub_name : sub_names) {
+  for (auto sub_name : sub_names) {
     if (sub_name.empty())
       continue;
     initials.push_back(sub_name[0]);
   }
   variants.insert(initials);
 
   // And, we're done.
   return variants;
 }
 
 bool AutofillProfileComparator::IsNameVariantOf(
     const base::string16& full_name_1,
     const base::string16& full_name_2) const {
   data_util::NameParts name_1_parts = data_util::SplitName(full_name_1);
 
   // Build the variants of full_name_1`s given, middle and family names.
   //
   // TODO(rogerm): Figure out whether or not we should break apart a compound
   // family name into variants (crbug/619051)
   const std::set<base::string16> given_name_variants =
       GetNamePartVariants(name_1_parts.given);
   const std::set<base::string16> middle_name_variants =
       GetNamePartVariants(name_1_parts.middle);
-  const base::string16& family_name = name_1_parts.family;
+  base::StringPiece16 family_name = name_1_parts.family;
 
   // Iterate over all full name variants of profile 2 and see if any of them
   // match the full name from profile 1.
-  for (const base::string16& given_name : given_name_variants) {
-    for (const base::string16& middle_name : middle_name_variants) {
+  for (base::StringPiece16 given_name : given_name_variants) {
+    for (base::StringPiece16 middle_name : middle_name_variants) {
       base::string16 candidate = base::CollapseWhitespace(
           base::JoinString({given_name, middle_name, family_name}, kSpace),
           true);
       if (candidate == full_name_2)
         return true;
     }
   }
 
   // Also check if the name is just composed of the user's initials. For
   // example, "thomas jefferson miller" could be composed as "tj miller".
@@ skipping 211 matching lines @@
   const base::string16& address2 = rewriter.Rewrite(NormalizeForComparison(
       p2.GetInfo(AutofillType(ADDRESS_HOME_STREET_ADDRESS), app_locale_)));
   if (CompareTokens(address1, address2) == DIFFERENT_TOKENS) {
     return false;
   }
 
   return true;
 }
 
 }  // namespace autofill