Split a MetricsLogStore object out of MetricsLogManager.

components/ukm/ukm_service_unittest.cc

Index: components/ukm/ukm_service_unittest.cc
diff --git a/components/ukm/ukm_service_unittest.cc b/components/ukm/ukm_service_unittest.cc
index f6b91c0dd1c76961cebb82d29ce4dadb27afcff1..be8090c2724d565c99244ac3a32f7e02d4cc14bd 100644
--- a/components/ukm/ukm_service_unittest.cc
+++ b/components/ukm/ukm_service_unittest.cc
@@ -49,8 +49,8 @@ class UkmServiceTest : public testing::Test {
         1000,  // byte limit
         0);
 
-    result_persisted_logs.DeserializeLogs();
-    result_persisted_logs.StageLog();
+    result_persisted_logs.LoadPersistedUnsentLogs();
+    result_persisted_logs.StageNextLog();
 
     std::string uncompressed_log_data;
     EXPECT_TRUE(compression::GzipUncompress(result_persisted_logs.staged_log(),