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

mojo/shell/tests/connect/connect_test_driver.cc

Index: mojo/shell/tests/connect/connect_test_driver.cc
diff --git a/mojo/shell/tests/connect/connect_test_driver.cc b/mojo/shell/tests/connect/connect_test_driver.cc
index b1bdce4c554e4e5a1d93648a457834b14973ab55..ace64df560a5d55659aa25f5f4fde6dbd1e08fa4 100644
--- a/mojo/shell/tests/connect/connect_test_driver.cc
+++ b/mojo/shell/tests/connect/connect_test_driver.cc
@@ -37,9 +37,8 @@
     connection->AddInterface<ClientProcessTest>(this);
     return true;
   }
-  bool ShellConnectionLost() override {
-    // TODO(rockot): http://crbug.com/596621. Should be able to remove this
-    // override entirely.
+  void ShellConnectionLost() override {
+    // TODO: This should exit cleanly.
     _exit(1);
   }