Report histogram creation results.

base/metrics/histogram.cc

Index: base/metrics/histogram.cc
diff --git a/base/metrics/histogram.cc b/base/metrics/histogram.cc
index ea4f8167fa28cc7098ce233cddbd7ed77fd23a77..83ad2cc5f7d0d0eced4cc07ec94c382ef0800867 100644
--- a/base/metrics/histogram.cc
+++ b/base/metrics/histogram.cc
@@ -211,9 +211,15 @@ HistogramBase* Histogram::Factory::Build() {
       FinalizePersistentHistogram(histogram_ref,
                                   histogram == tentative_histogram);
     }
+
+    // Update report on created histograms.
+    ReportHistogramActivity(histogram, HISTOGRAM_CREATED);
+  } else {
+    // Update report on lookup histograms.
+    ReportHistogramActivity(histogram, HISTOGRAM_LOOKUP);
   }
 
-  DCHECK_EQ(histogram_type_, histogram->GetHistogramType());
+  DCHECK_EQ(histogram_type_, histogram->GetHistogramType()) << name_;
   if (bucket_count_ != 0 &&
       !histogram->HasConstructionArguments(minimum_, maximum_, bucket_count_)) {
     // The construction arguments do not match the existing histogram.  This can