Break global impact of PersistentHistogramAllocator into a separate class.

base/metrics/persistent_histogram_allocator_unittest.cc

 // 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.
 
 #include "base/metrics/persistent_histogram_allocator.h"
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/bucket_ranges.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/persistent_memory_allocator.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
 class PersistentHistogramAllocatorTest : public testing::Test {
  protected:
   const int32_t kAllocatorMemorySize = 64 << 10;  // 64 KiB
 
   PersistentHistogramAllocatorTest() { CreatePersistentHistogramAllocator(); }
   ~PersistentHistogramAllocatorTest() override {
     DestroyPersistentHistogramAllocator();
   }
 
   void CreatePersistentHistogramAllocator() {
     allocator_memory_.reset(new char[kAllocatorMemorySize]);
 
-    PersistentHistogramAllocator::ReleaseGlobalAllocatorForTesting();
+    GlobalHistogramAllocator::ReleaseForTesting();
     memset(allocator_memory_.get(), 0, kAllocatorMemorySize);
-    PersistentHistogramAllocator::GetCreateHistogramResultHistogram();
-    PersistentHistogramAllocator::CreateGlobalAllocatorOnPersistentMemory(
+    GlobalHistogramAllocator::GetCreateHistogramResultHistogram();
+    GlobalHistogramAllocator::CreateWithPersistentMemory(
         allocator_memory_.get(), kAllocatorMemorySize, 0, 0,
         "PersistentHistogramAllocatorTest");
-    allocator_ =
-        PersistentHistogramAllocator::GetGlobalAllocator()->memory_allocator();
+    allocator_ = GlobalHistogramAllocator::Get()->memory_allocator();
   }
 
   void DestroyPersistentHistogramAllocator() {
     allocator_ = nullptr;
-    PersistentHistogramAllocator::ReleaseGlobalAllocatorForTesting();
+    GlobalHistogramAllocator::ReleaseForTesting();
   }
 
   std::unique_ptr<char[]> allocator_memory_;
   PersistentMemoryAllocator* allocator_ = nullptr;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PersistentHistogramAllocatorTest);
 };
 
 TEST_F(PersistentHistogramAllocatorTest, CreateAndIterateTest) {
@@ skipping 67 matching lines @@
 
   recovered = recovery.GetNextHistogram(&histogram_iter);
   ASSERT_TRUE(recovered);
   recovered->CheckName("TestCustomHistogram");
 
   recovered = recovery.GetNextHistogram(&histogram_iter);
   EXPECT_FALSE(recovered);
 }
 
 }  // namespace base