Move more client network code to //blimp/client/core/session.

blimp/client/core/session/network_event_observer.h

Index: blimp/client/core/session/network_event_observer.h
diff --git a/blimp/client/core/session/network_event_observer.h b/blimp/client/core/session/network_event_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..e443455877e337d3e735b26e8cd50c9385d39b84
--- /dev/null
+++ b/blimp/client/core/session/network_event_observer.h
@@ -0,0 +1,25 @@
+// 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_CORE_SESSION_NETWORK_EVENT_OBSERVER_H_
+#define BLIMP_CLIENT_CORE_SESSION_NETWORK_EVENT_OBSERVER_H_
+
+namespace blimp {
+namespace client {
+
+// A NetworkEventObserver is informed whenever changes happen to the connection
+// to the Blimp engine.
+class NetworkEventObserver {
+ public:
+  NetworkEventObserver() {}
+  virtual ~NetworkEventObserver() {}
+
+  virtual void OnConnected() = 0;
+  virtual void OnDisconnected(int result) = 0;
+};
+
+}  // namespace client
+}  // namespace blimp
+
+#endif  // BLIMP_CLIENT_CORE_SESSION_NETWORK_EVENT_OBSERVER_H_