Add ownership-transfer to histogram management calls.

base/metrics/sparse_histogram.cc

Index: base/metrics/sparse_histogram.cc
diff --git a/base/metrics/sparse_histogram.cc b/base/metrics/sparse_histogram.cc
index 5653456a29fb552470871f8611cb6337ec65bc50..afe677712dcffd74e1b4ceefdf5e91e48cab645e 100644
--- a/base/metrics/sparse_histogram.cc
+++ b/base/metrics/sparse_histogram.cc
@@ -25,10 +25,10 @@ HistogramBase* SparseHistogram::FactoryGet(const std::string& name,
 
   if (!histogram) {
     // To avoid racy destruction at shutdown, the following will be leaked.
-    HistogramBase* tentative_histogram = new SparseHistogram(name);
+    scoped_ptr<HistogramBase> tentative_histogram(new SparseHistogram(name));
     tentative_histogram->SetFlags(flags);
-    histogram =
-        StatisticsRecorder::RegisterOrDeleteDuplicate(tentative_histogram);
+    histogram = StatisticsRecorder::RegisterOrDeleteDuplicate(
+        std::move(tentative_histogram));
   }
   DCHECK_EQ(SPARSE_HISTOGRAM, histogram->GetHistogramType());
   return histogram;