Provide an abstraction for control interface

Only define/implement APIs for creating proxies for now.

Bug: 24194427
TEST=Compile for both Android and Chrome OS

Change-Id: I55d387abd0104ab808343f244be5acaa8a4c8549
diff --git a/control_interface.h b/control_interface.h
new file mode 100644
index 0000000..e5bbfd0
--- /dev/null
+++ b/control_interface.h
@@ -0,0 +1,45 @@
+//
+// Copyright (C) 2015 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef APMANAGER_CONTROL_INTERFACE_H_
+#define APMANAGER_CONTROL_INTERFACE_H_
+
+#include <base/callback.h>
+#include <base/macros.h>
+
+#include "apmanager/firewall_proxy_interface.h"
+#include "apmanager/shill_proxy_interface.h"
+
+namespace apmanager {
+
+// This is the Interface for an object factory that creates adaptor/proxy
+// objects
+class ControlInterface {
+ public:
+  virtual ~ControlInterface() {}
+
+  // Proxy creation APIs.
+  virtual std::unique_ptr<FirewallProxyInterface> CreateFirewallProxy(
+      const base::Closure& service_appeared_callback,
+      const base::Closure& service_vanished_callback) = 0;
+  virtual std::unique_ptr<ShillProxyInterface> CreateShillProxy(
+      const base::Closure& service_appeared_callback,
+      const base::Closure& service_vanished_callback) = 0;
+};
+
+}  // namespace apmanager
+
+#endif  // APMANAGER_CONTROL_INTERFACE_H_