Convert //base to use std::unique_ptr

base/metrics/sample_map.h

Index: base/metrics/sample_map.h
diff --git a/base/metrics/sample_map.h b/base/metrics/sample_map.h
index 2f24e1fa9e6dfddb8c10196d54ee905a9d26f1ef..7458e05e909c4bd58250e548fac8d1d442703c3c 100644
--- a/base/metrics/sample_map.h
+++ b/base/metrics/sample_map.h
@@ -11,10 +11,10 @@
 #include <stdint.h>
 
 #include <map>
+#include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram_base.h"
 #include "base/metrics/histogram_samples.h"
 
@@ -33,7 +33,7 @@ class BASE_EXPORT SampleMap : public HistogramSamples {
                   HistogramBase::Count count) override;
   HistogramBase::Count GetCount(HistogramBase::Sample value) const override;
   HistogramBase::Count TotalCount() const override;
-  scoped_ptr<SampleCountIterator> Iterator() const override;
+  std::unique_ptr<SampleCountIterator> Iterator() const override;
 
  protected:
   // Performs arithemetic. |op| is ADD or SUBTRACT.