leveldb: Add DBTracker for exposing databases to Chrome's memory-infra.

chrome/browser/android/history_report/delta_file_backend_leveldb.cc

Index: chrome/browser/android/history_report/delta_file_backend_leveldb.cc
diff --git a/chrome/browser/android/history_report/delta_file_backend_leveldb.cc b/chrome/browser/android/history_report/delta_file_backend_leveldb.cc
index 1ded0791c45f9aea74dd393fd96963e4415f9a48..88d4ddfd83260bf96dbca68e00194d6fea9c468e 100644
--- a/chrome/browser/android/history_report/delta_file_backend_leveldb.cc
+++ b/chrome/browser/android/history_report/delta_file_backend_leveldb.cc
@@ -12,6 +12,7 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/android/history_report/delta_file_commons.h"
+#include "third_party/leveldatabase/env_chromium.h"
 #include "third_party/leveldatabase/src/include/leveldb/comparator.h"
 #include "third_party/leveldatabase/src/include/leveldb/db.h"
 #include "third_party/leveldatabase/src/include/leveldb/iterator.h"
@@ -96,11 +97,11 @@ bool DeltaFileBackend::Init() {
   options.comparator = leveldb_cmp_.get();
   std::string path = path_.value();
   leveldb::DB* db = NULL;
-  leveldb::Status status = leveldb::DB::Open(options, path, &db);
+  leveldb::Status status = leveldb_env::DBRegistry::Open(options, path, &db);
   if (status.IsCorruption()) {
     LOG(WARNING) << "Deleting possibly-corrupt database";
     base::DeleteFile(path_, true);
-    status = leveldb::DB::Open(options, path, &db);
+    status = leveldb_env::DBRegistry::Open(options, path, &db);
   }
   if (status.ok()) {
     CHECK(db);