Add ownership-transfer to histogram management calls.

base/metrics/histogram_unittest.cc

Index: base/metrics/histogram_unittest.cc
diff --git a/base/metrics/histogram_unittest.cc b/base/metrics/histogram_unittest.cc
index beb6a71ede63c81168a851d099c9afbe8f2918bb..63c50a6b832551363f33836d99c5518d328c0b4a 100644
--- a/base/metrics/histogram_unittest.cc
+++ b/base/metrics/histogram_unittest.cc
@@ -189,23 +189,23 @@ TEST_P(HistogramTest, PersistentTest) {
       0, std::string(), false);
   recovery.CreateIterator(&iter);
 
-  recovered.reset(GetNextPersistentHistogram(&recovery, &iter));
+  recovered = GetNextPersistentHistogram(&recovery, &iter);
   ASSERT_TRUE(recovered);
   recovered->CheckName("TestHistogram");
 
-  recovered.reset(GetNextPersistentHistogram(&recovery, &iter));
+  recovered = GetNextPersistentHistogram(&recovery, &iter);
   ASSERT_TRUE(recovered);
   recovered->CheckName("TestLinearHistogram");
 
-  recovered.reset(GetNextPersistentHistogram(&recovery, &iter));
+  recovered = GetNextPersistentHistogram(&recovery, &iter);
   ASSERT_TRUE(recovered);
   recovered->CheckName("TestBooleanHistogram");
 
-  recovered.reset(GetNextPersistentHistogram(&recovery, &iter));
+  recovered = GetNextPersistentHistogram(&recovery, &iter);
   ASSERT_TRUE(recovered);
   recovered->CheckName("TestCustomHistogram");
 
-  recovered.reset(GetNextPersistentHistogram(&recovery, &iter));
+  recovered = GetNextPersistentHistogram(&recovery, &iter);
   EXPECT_FALSE(recovered);
 
   // Use standard macros (but with fixed samples)