Add reporting library, use it

1 files changed, 2 insertions, 2 deletions

diff --git a/test/cpp/qps/histogram.h b/test/cpp/qps/histogram.h
index 7ba00e94c3..fbb80abf87 100644
--- a/test/cpp/qps/histogram.h
+++ b/test/cpp/qps/histogram.h
@@ -50,10 +50,10 @@ class Histogram {
 
   void Merge(Histogram* h) { gpr_histogram_merge(impl_, h->impl_); }
   void Add(double value) { gpr_histogram_add(impl_, value); }
-  double Percentile(double pctile) {
+  double Percentile(double pctile) const {
     return gpr_histogram_percentile(impl_, pctile);
   }
-  double Count() { return gpr_histogram_count(impl_); }
+  double Count() const { return gpr_histogram_count(impl_); }
   void Swap(Histogram* other) { std::swap(impl_, other->impl_); }
   void FillProto(HistogramData* p) {
     size_t n;