Add ownership-transfer to histogram management calls.

chromecast/base/metrics/grouped_histogram.cc

Index: chromecast/base/metrics/grouped_histogram.cc
diff --git a/chromecast/base/metrics/grouped_histogram.cc b/chromecast/base/metrics/grouped_histogram.cc
index 1101a7992c55f6f25658d743d992404087298065..34bf5382e161f6b5c223aab6aa7f17cb5636e9ec 100644
--- a/chromecast/base/metrics/grouped_histogram.cc
+++ b/chromecast/base/metrics/grouped_histogram.cc
@@ -143,20 +143,23 @@ void PreregisterHistogram(const std::string& name,
   DCHECK(!base::StatisticsRecorder::FindHistogram(name))
       << "Failed to preregister " << name << ", Histogram already exists.";
 
-  // To avoid racy destruction at shutdown, the following will be leaked.
-  base::BucketRanges* ranges = new base::BucketRanges(bucket_count + 1);
-  base::Histogram::InitializeBucketRanges(minimum, maximum, ranges);
+  scoped_ptr<base::BucketRanges> ranges(
+      new base::BucketRanges(bucket_count + 1));
+  base::Histogram::InitializeBucketRanges(minimum, maximum, ranges.get());
   const base::BucketRanges* registered_ranges =
-      base::StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges);
+      base::StatisticsRecorder::RegisterOrDeleteDuplicateRanges(
+          std::move(ranges));
 
-  GroupedHistogram* tentative_histogram =
-      new GroupedHistogram(name, minimum, maximum, registered_ranges);
+  scoped_ptr<GroupedHistogram> tentative_histogram(
+      new GroupedHistogram(name, minimum, maximum, registered_ranges));
 
   tentative_histogram->SetFlags(flags);
+  const void* allocated_histogram = tentative_histogram.get();
   base::HistogramBase* histogram =
-      base::StatisticsRecorder::RegisterOrDeleteDuplicate(tentative_histogram);
+      base::StatisticsRecorder::RegisterOrDeleteDuplicate(
+          std::move(tentative_histogram));
 
-  DCHECK_EQ(histogram, tentative_histogram);
+  DCHECK_EQ(histogram, allocated_histogram);
   DCHECK_EQ(base::HISTOGRAM, histogram->GetHistogramType());
   DCHECK(histogram->HasConstructionArguments(minimum, maximum, bucket_count));
 }