Report histogram creation results.

base/metrics/sparse_histogram.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/metrics/sparse_histogram.h"
 
 #include <utility>
 
 #include "base/metrics/metrics_hashes.h"
 #include "base/metrics/sample_map.h"
@@ skipping 11 matching lines @@
 HistogramBase* SparseHistogram::FactoryGet(const std::string& name,
                                            int32_t flags) {
   HistogramBase* histogram = StatisticsRecorder::FindHistogram(name);
 
   if (!histogram) {
     // To avoid racy destruction at shutdown, the following will be leaked.
     HistogramBase* tentative_histogram = new SparseHistogram(name);
     tentative_histogram->SetFlags(flags);
     histogram =
         StatisticsRecorder::RegisterOrDeleteDuplicate(tentative_histogram);
+    ReportHistogramActivity(*histogram, HISTOGRAM_CREATED);
+  } else {
+    ReportHistogramActivity(*histogram, HISTOGRAM_LOOKUP);
   }
   DCHECK_EQ(SPARSE_HISTOGRAM, histogram->GetHistogramType());
   return histogram;
 }
 
 SparseHistogram::~SparseHistogram() {}
 
 uint64_t SparseHistogram::name_hash() const {
   return samples_.id();
 }
@@ skipping 155 matching lines @@
                                        std::string* output) const {
   StringAppendF(output,
                 "Histogram: %s recorded %d samples",
                 histogram_name().c_str(),
                 total_count);
   if (flags() & ~kHexRangePrintingFlag)
     StringAppendF(output, " (flags = 0x%x)", flags() & ~kHexRangePrintingFlag);
 }
 
 }  // namespace base