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

base/histogram.h

Index: base/histogram.h
===================================================================
--- base/histogram.h	(revision 7938)
+++ base/histogram.h	(working copy)
@@ -370,7 +370,19 @@
   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.
 //------------------------------------------------------------------------------