Mojo: Add an extremely skeletal mojo_shell_tests.

mojo/shell/shell_test_base.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "net/spdy/mock_spdy_framer_visitor.h"
+#include "mojo/shell/shell_test_base.h"
 
-namespace net {
-
+namespace mojo {
+namespace shell {
 namespace test {
 
-MockSpdyFramerVisitor::MockSpdyFramerVisitor() {}
+ShellTestBase::ShellTestBase() {
+}
 
-MockSpdyFramerVisitor::~MockSpdyFramerVisitor() {}
+ShellTestBase::~ShellTestBase() {
+}
 
 }  // namespace test
-
-}  // namespace net
+}  // namespace shell
+}  // namespace mojo