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..55ca1b9e0bf6a16a943f4839e91975988b9d4b70 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,
+                             base::TimeDelta sample,
+                             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.