Allow to Suspend/Resume the ActionProcessor.

This patch implements the core functionality of suspend/resume actions
from the ActionProcessor. No actions support suspend/resume yet.

Bug: 27047026
TEST=Added unittets, tested on edison-eng.

Change-Id: Ib9600098dbccf05fc30f10f0add4a5bc87892b66
diff --git a/common/mock_action_processor.h b/common/mock_action_processor.h
new file mode 100644
index 0000000..04275c1
--- /dev/null
+++ b/common/mock_action_processor.h
@@ -0,0 +1,34 @@
+//
+// Copyright (C) 2010 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 UPDATE_ENGINE_COMMON_MOCK_ACTION_PROCESSOR_H_
+#define UPDATE_ENGINE_COMMON_MOCK_ACTION_PROCESSOR_H_
+
+#include <gmock/gmock.h>
+
+#include "update_engine/common/action.h"
+
+namespace chromeos_update_engine {
+
+class MockActionProcessor : public ActionProcessor {
+ public:
+  MOCK_METHOD0(StartProcessing, void());
+  MOCK_METHOD1(EnqueueAction, void(AbstractAction* action));
+};
+
+}  // namespace chromeos_update_engine
+
+#endif  // UPDATE_ENGINE_COMMON_MOCK_ACTION_PROCESSOR_H_