Skeleton code of SparseHistogram

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>
+
 namespace base {
 
 const HistogramBase::Sample HistogramBase::kSampleType_MAX = INT_MAX;
 
 HistogramBase::HistogramBase(const std::string& name)
-    : histogram_name_(name) {}
+    : histogram_name_(name),
+      flags_(kNoFlags) {}
 
 HistogramBase::~HistogramBase() {}
 
+void HistogramBase::SetFlags(int32 flags) {
+  flags_ |= flags;
+}
+
+void HistogramBase::ClearFlags(int32 flags) {
+  flags_ &= ~flags;
+}
+
 }  // namespace base