Use of base::StringPairs appropriately in base

base/strings/string_split_unittest.cc

 // Copyright (c) 2012 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 "base/strings/string_split.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 13 matching lines @@
   SplitString(WideToUTF16(str), c, &result16);
   for (size_t i = 0; i < result16.size(); ++i)
     result->push_back(UTF16ToWide(result16[i]));
 }
 #endif
 
 }  // anonymous namespace
 
 class SplitStringIntoKeyValuePairsTest : public testing::Test {
  protected:
-  std::vector<std::pair<std::string, std::string> > kv_pairs;
+  base::StringPairs kv_pairs;
 };
 
 TEST_F(SplitStringIntoKeyValuePairsTest, EmptyString) {
   EXPECT_TRUE(SplitStringIntoKeyValuePairs(std::string(),
                                            ':',  // Key-value delimiter
                                            ',',  // Key-value pair delimiter
                                            &kv_pairs));
   EXPECT_TRUE(kv_pairs.empty());
 }
 
@@ skipping 272 matching lines @@
     SplitStringAlongWhitespace(data[i].input, &results);
     ASSERT_EQ(data[i].expected_result_count, results.size());
     if (data[i].expected_result_count > 0)
       ASSERT_EQ(data[i].output1, results[0]);
     if (data[i].expected_result_count > 1)
       ASSERT_EQ(data[i].output2, results[1]);
   }
 }
 
 }  // namespace base