Adding UseCounter specific for extensions

third_party/WebKit/Source/platform/testing/HistogramTester.h

 // Copyright 2016 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 HistogramTester_h
 #define HistogramTester_h
 
 #include "platform/Histogram.h"
 #include <memory>
 
@@ skipping 10 matching lines @@
   ~HistogramTester();
 
   void ExpectUniqueSample(const std::string& name,
                           base::HistogramBase::Sample,
                           base::HistogramBase::Count) const;
   void ExpectBucketCount(const std::string& name,
                          base::HistogramBase::Sample,
                          base::HistogramBase::Count) const;
   void ExpectTotalCount(const std::string& name,
                         base::HistogramBase::Count) const;
+  base::HistogramBase::Count GetBucketCount(const std::string& name,
+                                            base::HistogramBase::Sample) const;
 
  private:
   std::unique_ptr<base::HistogramTester> histogram_tester_;
 };
 
 }  // namespace blink
 
 #endif  // HistogramTester_h