Report histogram creation results.

base/metrics/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.
 
 // Histogram is an object that aggregates statistics, and can summarize them in
 // various forms, including ASCII graphical, HTML, and numerically (as a
 // vector of numbers corresponding to each of the aggregating buckets).
 // See header file for details and examples.
 
 #include "base/metrics/histogram.h"
@@ skipping 193 matching lines @@
 
     FillHistogram(tentative_histogram);
     histogram =
         StatisticsRecorder::RegisterOrDeleteDuplicate(tentative_histogram);
 
     // Persistent histograms need some follow-up processing.
     if (histogram_ref) {
       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
     // come about if an extension updates in the middle of a chrome run and has
     // changed one of them, or simply by bad code within Chrome itself.  We
     // return NULL here with the expectation that bad code in Chrome will crash
     // on dereference, but extension/Pepper APIs will guard against NULL and not
     // crash.
     DLOG(ERROR) << "Histogram " << name_ << " has bad construction arguments";
     return nullptr;
@@ skipping 928 matching lines @@
     Sample sample = custom_ranges[i];
     if (sample < 0 || sample > HistogramBase::kSampleType_MAX - 1)
       return false;
     if (sample != 0)
       has_valid_range = true;
   }
   return has_valid_range;
 }
 
 }  // namespace base