Revert 212378 "Add a HistogramRecorder class and use cases."

trunk/src/base/test/histogram_recorder.h

-// Copyright 2013 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_TEST_HISTOGRAM_RECORDER_H_
-#define BASE_TEST_HISTOGRAM_RECORDER_H_
-
-#include <map>
-
-#include "base/memory/scoped_ptr.h"
-#include "base/metrics/histogram_samples.h"
-
-namespace base {
-
-// This class acts as a differential reader for histogram samples, enabling
-// tests to check that metrics were sent as they should be.
-class HistogramRecorder {
- public:
-  HistogramRecorder();
-  virtual ~HistogramRecorder();
-
-  // Returns the histogram data accumulated since this instance was created.
-  // Returns NULL if no samples are available.
-  scoped_ptr<HistogramSamples> GetHistogramSamplesSinceCreation(
-      const std::string& histogram_name);
-
- private:
-  // Used to determine the histogram changes made during this instance's
-  // lifecycle.
-  std::map<std::string, HistogramSamples*> original_samples_;
-};
-
-}  // namespace base
-
-#endif  // BASE_TEST_HISTOGRAM_RECORDER_H_