Move session into //blimp/client/app and update GN files.

blimp/client/session/test_client_session.h

Index: blimp/client/session/test_client_session.h
diff --git a/blimp/client/session/test_client_session.h b/blimp/client/session/test_client_session.h
deleted file mode 100644
index b81a321b3fc586dd2375616dd7ec771f6145439a..0000000000000000000000000000000000000000
--- a/blimp/client/session/test_client_session.h
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright 2016 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.
-
-#ifndef BLIMP_CLIENT_SESSION_TEST_CLIENT_SESSION_H_
-#define BLIMP_CLIENT_SESSION_TEST_CLIENT_SESSION_H_
-
-#include "blimp/client/session/blimp_client_session.h"
-
-namespace blimp {
-namespace client {
-
-class TestClientSession : public client::BlimpClientSession {
- public:
-  TestClientSession();
-  ~TestClientSession() override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(TestClientSession);
-};
-
-}  // namespace client
-}  // namespace blimp
-
-#endif  // BLIMP_CLIENT_SESSION_TEST_CLIENT_SESSION_H_