Expose macros from base/metrics/histogram_macros.h as functions

base/test/histogram_tester.h

Index: base/test/histogram_tester.h
diff --git a/base/test/histogram_tester.h b/base/test/histogram_tester.h
index cd8534acd459a852df936aeb0e6a7cb8514c6482..ec10e3763ea690c94aed8fc15b087189e62bf8ca 100644
--- a/base/test/histogram_tester.h
+++ b/base/test/histogram_tester.h
@@ -15,6 +15,7 @@
 #include "base/macros.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/histogram_base.h"
+#include "base/time/time.h"
 
 namespace base {
 
@@ -53,6 +54,12 @@ class HistogramTester {
   void ExpectTotalCount(const std::string& name,
                         base::HistogramBase::Count count) const;
 
+  // We know exact number of samples for buckets corresponding to a
+  // time interval. Other intervals may have samples too.
+  void ExpectTimeBucketCount(const std::string& name,
+                             const base::TimeDelta& sample,

[Alexei Svitkine (slow), 2016/11/12 00:51:14]

Nit: I think base::TimeDelta should be passed by value. See its header.

[nikunjb, 2016/11/12 01:35:15]

Done. Also fixed the TimeDelta used in histogram_functions

+                             base::HistogramBase::Count count) const;
+
   // Returns a list of all of the buckets recorded since creation of this
   // object, as vector<Bucket>, where the Bucket represents the min boundary of
   // the bucket and the count of samples recorded to that bucket since creation.