Enable sharding of AllocationRegister on desktop.

third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.h

Index: third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.h
diff --git a/third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.h b/third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.h
index eb379de310ce5152e55d8bd1513d788b811e1059..808aa05fabdf08b603120c056ab2757cf5dd5eed 100644
--- a/third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.h
+++ b/third_party/WebKit/Source/platform/PartitionAllocMemoryDumpProvider.h
@@ -6,18 +6,10 @@
 #define PartitionAllocMemoryDumpProvider_h
 
 #include "base/trace_event/memory_dump_provider.h"
+#include "base/trace_event/sharded_allocation_register.h"
 #include "platform/wtf/Noncopyable.h"
-#include "platform/wtf/ThreadingPrimitives.h"
 #include "public/platform/WebCommon.h"
 
-namespace base {
-namespace trace_event {
-
-class AllocationRegister;
-
-}  // namespace trace_event
-}  // namespace base
-
 namespace blink {
 
 class BLINK_PLATFORM_EXPORT PartitionAllocMemoryDumpProvider final
@@ -42,9 +34,7 @@ class BLINK_PLATFORM_EXPORT PartitionAllocMemoryDumpProvider final
  private:
   PartitionAllocMemoryDumpProvider();
 
-  Mutex allocation_register_mutex_;
-  std::unique_ptr<base::trace_event::AllocationRegister> allocation_register_;
-  bool is_heap_profiling_enabled_;
+  base::trace_event::ShardedAllocationRegister allocation_register_;
 };
 
 }  // namespace blink