Add support to increase a UMA histogram bucket by an aribitrary integer.

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 1bc1f6eb6fe78bf4a48576f60e3da694a74da932..820ac3b8be870158febdd801ebac545d8a970669 100644
--- a/base/metrics/histogram_base.h
+++ b/base/metrics/histogram_base.h
@@ -120,6 +120,7 @@ class BASE_EXPORT HistogramBase {
                                         size_t expected_bucket_count) const = 0;
 
   virtual void Add(Sample value) = 0;
+  virtual void MultiAdd(Sample value, int repetition) = 0;

[Alexei Svitkine (slow), 2015/07/31 15:39:27]

How about naming it AddCount(value, count). Also add some comments. Update your
tests to the new name too. Also, you still use "repetition" as a param name in
some of the files. Please update them.

[amohammadkhan, 2015/08/03 17:30:43]

Done.

 
   // 2 convenient functions that call Add(Sample).
   void AddTime(const TimeDelta& time);