Quit the message loop by default in ShellConnectionLost when ApplicationRunner is used

components/leveldb/leveldb_app.cc

Index: components/leveldb/leveldb_app.cc
diff --git a/components/leveldb/leveldb_app.cc b/components/leveldb/leveldb_app.cc
index aad49e2882cd472f320252d7ffee99d56b3256a5..4ac0ca0d83253e52dca0eb910796d05d275a2248 100644
--- a/components/leveldb/leveldb_app.cc
+++ b/components/leveldb/leveldb_app.cc
@@ -25,11 +25,6 @@ bool LevelDBApp::AcceptConnection(mojo::Connection* connection) {
   return true;
 }
 
-void LevelDBApp::ShellConnectionLost() {
-  // TODO: This should exit cleanly.
-  _exit(1);
-}
-
 void LevelDBApp::Create(mojo::Connection* connection,
                         mojo::InterfaceRequest<LevelDBService> request) {
   bindings_.AddBinding(service_.get(), std::move(request));