Break global impact of PersistentHistogramAllocator into a separate class.

base/metrics/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/histogram.h"
 
 #include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 50 matching lines @@
 
   void UninitializeStatisticsRecorder() {
     delete statistics_recorder_;
     statistics_recorder_ = NULL;
   }
 
   void CreatePersistentHistogramAllocator() {
     // 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, "HistogramAllocatorTest");
-    allocator_ =
-        PersistentHistogramAllocator::GetGlobalAllocator()->memory_allocator();
+    allocator_ = GlobalHistogramAllocator::Get()->memory_allocator();
   }
 
   void DestroyPersistentHistogramAllocator() {
     allocator_ = nullptr;
-    PersistentHistogramAllocator::ReleaseGlobalAllocatorForTesting();
+    GlobalHistogramAllocator::ReleaseForTesting();
   }
 
   const bool use_persistent_histogram_allocator_;
 
   StatisticsRecorder* statistics_recorder_ = nullptr;
   std::unique_ptr<char[]> allocator_memory_;
   PersistentMemoryAllocator* allocator_ = nullptr;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(HistogramTest);
@@ skipping 611 matching lines @@
   // CustomHistogram needs at least 1 valid range.
   custom_ranges.clear();
   custom_ranges.push_back(0);
   EXPECT_DEATH(CustomHistogram::FactoryGet("BadRangesCustom3", custom_ranges,
                                            HistogramBase::kNoFlags),
                "");
 }
 #endif
 
 }  // namespace base