Use leveldb_env::OpenDB() to open leveldb databases.

components/leveldb/leveldb_database_impl.cc

Index: components/leveldb/leveldb_database_impl.cc
diff --git a/components/leveldb/leveldb_database_impl.cc b/components/leveldb/leveldb_database_impl.cc
index 02b1a2d83cc70f4c49b5f5e8680fd6bc80acafbb..d7ff2298de7eaf7b14553021fb4c0eb9b19ea9a9 100644
--- a/components/leveldb/leveldb_database_impl.cc
+++ b/components/leveldb/leveldb_database_impl.cc
@@ -16,6 +16,7 @@
 #include "base/trace_event/memory_dump_manager.h"
 #include "components/leveldb/env_mojo.h"
 #include "components/leveldb/public/cpp/util.h"
+#include "third_party/leveldatabase/env_chromium.h"
 #include "third_party/leveldatabase/src/include/leveldb/db.h"
 #include "third_party/leveldatabase/src/include/leveldb/write_batch.h"
 
@@ -308,11 +309,10 @@ bool LevelDBDatabaseImpl::OnMemoryDump(
                          cache_->TotalCharge());
   }
 
-  const char* system_allocator_name =
-      base::trace_event::MemoryDumpManager::GetInstance()
-          ->system_allocator_pool_name();
-  if (system_allocator_name)
-    pmd->AddSuballocation(mad->guid(), system_allocator_name);
+  // All leveldb databases are already dumped by leveldb_env::DBTracker. Add
+  // an edge to avoid double counting.
+  pmd->AddSuballocation(mad->guid(),
+                        leveldb_env::DBTracker::GetMemoryDumpName(db_.get()));
 
   if (memory_dump_id_) {
     auto* global_dump = pmd->CreateSharedGlobalAllocatorDump(*memory_dump_id_);