Consolidate serialization code in base::HistogramDeltasSerializer.

base/metrics/histogram_base.h

Index: base/metrics/histogram_base.h
diff --git a/base/metrics/histogram_base.h b/base/metrics/histogram_base.h
index 46636477f3e3396dbdeb6edf62f828c49e8e59f4..4248bd84a4c3136f6f2a1ee60483fa54e14ce2e9 100644
--- a/base/metrics/histogram_base.h
+++ b/base/metrics/histogram_base.h
@@ -6,6 +6,7 @@
 #define BASE_METRICS_HISTOGRAM_BASE_H_
 
 #include <string>
+#include <vector>
 
 #include "base/atomicops.h"
 #include "base/base_export.h"
@@ -43,10 +44,6 @@ std::string HistogramTypeToString(HistogramType type);
 BASE_EXPORT_PRIVATE HistogramBase* DeserializeHistogramInfo(
     PickleIterator* iter);
 
-// Create or find existing histogram and add the samples from pickle.
-// Silently returns when seeing any data problem in the pickle.
-BASE_EXPORT void DeserializeHistogramAndAddSamples(PickleIterator* iter);
-
 ////////////////////////////////////////////////////////////////////////////////
 
 class BASE_EXPORT HistogramBase {