Collect some metrics on nosniff. There is some concern that respecting this ...

base/histogram.h

 // Copyright (c) 2006-2008 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).
 
 // It supports calls to accumulate either time intervals (which are processed
 // as integral number of milliseconds), or arbitrary integral units.
@@ skipping 352 matching lines @@
  private:
   // For some ranges, we store a printable description of a bucket range.
   // If there is no desciption, then GetAsciiBucketRange() uses parent class
   // to provide a description.
   typedef std::map<Sample, std::string> BucketDescriptionMap;
   BucketDescriptionMap bucket_description_;
 
   DISALLOW_EVIL_CONSTRUCTORS(LinearHistogram);
 };
 
+//------------------------------------------------------------------------------
+
+// BooleanHistogram is a histogram for booleans.
+class BooleanHistogram : public LinearHistogram {
+ public:
+  BooleanHistogram(const wchar_t* name) : LinearHistogram(name, 0, 2, 3) {}
+
+  virtual void AddBoolean(bool value) { Add(value ? 1 : 0); }
+
+ private:
+  DISALLOW_EVIL_CONSTRUCTORS(BooleanHistogram);
+};
 
 //------------------------------------------------------------------------------
 // This section provides implementation for ThreadSafeHistogram.
 //------------------------------------------------------------------------------
 
 class ThreadSafeHistogram : public Histogram {
  public:
   ThreadSafeHistogram(const wchar_t* name, Sample minimum,
                       Sample maximum, size_t bucket_count);
 
@@ skipping 60 matching lines @@
   static Lock* lock_;
 
   // Dump all known histograms to log.
   static bool dump_on_exit_;
 
   DISALLOW_EVIL_CONSTRUCTORS(StatisticsRecorder);
 };
 
 #endif  // BASE_HISTOGRAM_H__