base: Use std::move() instead of Pass() for real movable types.

base/metrics/histogram_base.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/metrics/histogram_base.h"
 
 #include <climits>
+#include <utility>
 
 #include "base/json/json_string_value_serializer.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/histogram_samples.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/pickle.h"
 #include "base/process/process_handle.h"
@@ skipping 89 matching lines @@
   GetCountAndBucketData(&count, &sum, buckets.get());
   scoped_ptr<DictionaryValue> parameters(new DictionaryValue());
   GetParameters(parameters.get());
 
   JSONStringValueSerializer serializer(output);
   DictionaryValue root;
   root.SetString("name", histogram_name());
   root.SetInteger("count", count);
   root.SetDouble("sum", static_cast<double>(sum));
   root.SetInteger("flags", flags());
-  root.Set("params", parameters.Pass());
-  root.Set("buckets", buckets.Pass());
+  root.Set("params", std::move(parameters));
+  root.Set("buckets", std::move(buckets));
   root.SetInteger("pid", GetCurrentProcId());
   serializer.Serialize(root);
 }
 
 void HistogramBase::FindAndRunCallback(HistogramBase::Sample sample) const {
   if ((flags() & kCallbackExists) == 0)
     return;
 
   StatisticsRecorder::OnSampleCallback cb =
       StatisticsRecorder::FindCallback(histogram_name());
@@ skipping 26 matching lines @@
   return result;
 }
 
 void HistogramBase::WriteAsciiBucketValue(Count current,
                                           double scaled_sum,
                                           std::string* output) const {
   StringAppendF(output, " (%d = %3.1f%%)", current, current/scaled_sum);
 }
 
 }  // namespace base