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

components/leveldb_proto/leveldb_database.cc

Index: components/leveldb_proto/leveldb_database.cc
diff --git a/components/leveldb_proto/leveldb_database.cc b/components/leveldb_proto/leveldb_database.cc
index 9791c19d5ad9e8f3e124e2c263f52c958bf49057..d7aeb7ac20252bf20f4bcabf42cdf7407aaf6774 100644
--- a/components/leveldb_proto/leveldb_database.cc
+++ b/components/leveldb_proto/leveldb_database.cc
@@ -62,12 +62,12 @@ bool LevelDB::InitWithOptions(const base::FilePath& database_dir,
   std::string path = database_dir.AsUTF8Unsafe();
 
   leveldb::DB* db = NULL;
-  leveldb::Status status = leveldb::DB::Open(options, path, &db);
+  leveldb::Status status = leveldb_env::DBRegistry::Open(options, path, &db);
   if (open_histogram_)
     open_histogram_->Add(leveldb_env::GetLevelDBStatusUMAValue(status));
   if (status.IsCorruption()) {
     base::DeleteFile(database_dir, true);
-    status = leveldb::DB::Open(options, path, &db);
+    status = leveldb_env::DBRegistry::Open(options, path, &db);
   }
 
   if (status.ok()) {