Convert //base to use std::unique_ptr

base/metrics/sample_vector.cc

Index: base/metrics/sample_vector.cc
diff --git a/base/metrics/sample_vector.cc b/base/metrics/sample_vector.cc
index ccb94317250df3b6aa2f792c183b7f9d66c95656..9c6453e94335073df50228b18b6abe8f66727f4b 100644
--- a/base/metrics/sample_vector.cc
+++ b/base/metrics/sample_vector.cc
@@ -65,8 +65,8 @@ Count SampleVector::GetCountAtIndex(size_t bucket_index) const {
   return subtle::NoBarrier_Load(&counts_[bucket_index]);
 }
 
-scoped_ptr<SampleCountIterator> SampleVector::Iterator() const {
-  return scoped_ptr<SampleCountIterator>(
+std::unique_ptr<SampleCountIterator> SampleVector::Iterator() const {
+  return std::unique_ptr<SampleCountIterator>(
       new SampleVectorIterator(counts_, counts_size_, bucket_ranges_));
 }