Histogram argument related change

base/metrics/histogram_base.h

 // 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.
 
 #ifndef BASE_METRICS_HISTOGRAM_BASE_H_
 #define BASE_METRICS_HISTOGRAM_BASE_H_
 
 #include <string>
 
 #include "base/base_export.h"
@@ skipping 33 matching lines @@
   HistogramBase(const std::string& name);
   virtual ~HistogramBase();
 
   std::string histogram_name() const { return histogram_name_; }
 
   // Operations with Flags enum.
   int32 flags() const { return flags_; }
   void SetFlags(int32 flags);
   void ClearFlags(int32 flags);
 
+  // Whether the histogram has construction arguments as parameters specified.
+  // For histograms that don't have the concept of minimum, maximum or
+  // bucket_count, this function always returns false.
+  virtual bool HasConstructionArguments(Sample minimum,
+                                        Sample maximum,
+                                        size_t bucket_count) const = 0;
+
   virtual void Add(Sample value) = 0;
 
+  // Snapshot the current complete set of sample data.
+  // Override with atomic/locked snapshot if needed.
   virtual scoped_ptr<HistogramSamples> SnapshotSamples() const = 0;
 
   // The following methods provide graphical histogram displays.
   virtual void WriteHTMLGraph(std::string* output) const = 0;
   virtual void WriteAscii(std::string* output) const = 0;
 
   // Produce a JSON representation of the histogram. This is implemented with
   // the help of GetParameters and GetCountAndBucketData; overwrite them to
   // customize the output.
   void WriteJSON(std::string* output) const;
 
 protected:
   // Writes information about the construction parameters in |params|.
   virtual void GetParameters(DictionaryValue* params) const = 0;
 
   // Writes information about the current (non-empty) buckets and their sample
   // counts to |buckets| and the total sample count to |count|.
   virtual void GetCountAndBucketData(Count* count,
                                      ListValue* buckets) const = 0;
  private:
   const std::string histogram_name_;
   int32 flags_;
 
   DISALLOW_COPY_AND_ASSIGN(HistogramBase);
 };
 
 }  // namespace base
 
 #endif  // BASE_METRICS_HISTOGRAM_BASE_H_