Break global impact of PersistentHistogramAllocator into a separate class.

base/metrics/sparse_histogram_unittest.cc

 // 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.
 
 #include "base/metrics/sparse_histogram.h"
 
 #include <memory>
 #include <string>
 
 #include "base/metrics/histogram_base.h"
@@ skipping 42 matching lines @@
 
   void UninitializeStatisticsRecorder() {
     delete statistics_recorder_;
     statistics_recorder_ = NULL;
   }
 
   void CreatePersistentMemoryAllocator() {
     // By getting the results-histogram before any persistent allocator
     // is attached, that histogram is guaranteed not to be stored in
     // any persistent memory segment (which simplifies some tests).
-    PersistentHistogramAllocator::GetCreateHistogramResultHistogram();
+    GlobalHistogramAllocator::GetCreateHistogramResultHistogram();
 
-    PersistentHistogramAllocator::CreateGlobalAllocatorOnLocalMemory(
+    GlobalHistogramAllocator::CreateWithLocalMemory(
         kAllocatorMemorySize, 0, "SparseHistogramAllocatorTest");
-    allocator_ =
-        PersistentHistogramAllocator::GetGlobalAllocator()->memory_allocator();
+    allocator_ = GlobalHistogramAllocator::Get()->memory_allocator();
   }
 
   void DestroyPersistentMemoryAllocator() {
     allocator_ = nullptr;
-    PersistentHistogramAllocator::ReleaseGlobalAllocatorForTesting();
+    GlobalHistogramAllocator::ReleaseForTesting();
   }
 
   std::unique_ptr<SparseHistogram> NewSparseHistogram(const std::string& name) {
     return std::unique_ptr<SparseHistogram>(new SparseHistogram(name));
   }
 
   const bool use_persistent_histogram_allocator_;
 
   StatisticsRecorder* statistics_recorder_;
-  std::unique_ptr<char[]> allocator_memory_;
   PersistentMemoryAllocator* allocator_ = nullptr;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SparseHistogramTest);
 };
 
 // Run all HistogramTest cases with both heap and persistent memory.
 INSTANTIATE_TEST_CASE_P(HeapAndPersistent,
                         SparseHistogramTest,
                         testing::Bool());
@@ skipping 180 matching lines @@
   TimeDelta add_ticks = TimeTicks::Now() - add_start;
   int64_t add_ms = add_ticks.InMilliseconds();
 
   VLOG(1) << kTestAddCount << " histogram adds took " << add_ms
           << "ms or about "
           << (add_ms * 1000000) / kTestAddCount
           << "ns each.";
 }
 
 }  // namespace base