Break global impact of PersistentHistogramAllocator into a separate class.

base/metrics/persistent_histogram_allocator_unittest.cc

Index: base/metrics/persistent_histogram_allocator_unittest.cc
diff --git a/base/metrics/persistent_histogram_allocator_unittest.cc b/base/metrics/persistent_histogram_allocator_unittest.cc
index 922245faf523afd103774fae413dfc42075d8923..4f0d44689015c6f0d4df85a2512567fc7aed9354 100644
--- a/base/metrics/persistent_histogram_allocator_unittest.cc
+++ b/base/metrics/persistent_histogram_allocator_unittest.cc
@@ -25,19 +25,18 @@ class PersistentHistogramAllocatorTest : public testing::Test {
   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_;