Use base::StringPairs where appropriate from /chrome

chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc

Index: chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc
diff --git a/chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc b/chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc
index ce3560f65903be41577b8e6b8f4cd5bd7483b3ef..ceea737d04c2034909f40e6a423e4b91947e516a 100644
--- a/chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc
+++ b/chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc
@@ -8,6 +8,7 @@
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
+#include "base/strings/string_split.h"
 #include "chrome/browser/chromeos/drive/drive.pb.h"
 #include "chrome/browser/chromeos/drive/test_util.h"
 #include "content/public/test/test_browser_thread_bundle.h"
@@ -198,8 +199,7 @@ TEST_F(ResourceMetadataStorageTest, GetIdByResourceId) {
 TEST_F(ResourceMetadataStorageTest, GetChildren) {
   const std::string parents_id[] = { "mercury", "venus", "mars", "jupiter",
                                      "saturn" };
-  std::vector<std::vector<std::pair<std::string, std::string> > >
-      children_name_id(arraysize(parents_id));
+  std::vector<base::StringPairs> children_name_id(arraysize(parents_id));
   // Skip children_name_id[0/1] here because Mercury and Venus have no moon.
   children_name_id[2].push_back(std::make_pair("phobos", "mars_i"));
   children_name_id[2].push_back(std::make_pair("deimos", "mars_ii"));