update_engine: Standarize mock/fake filenames.

Mock classes implement mostly MOCK_METHOD* methods used with gmock.
Those classes should be named with the prefix "Mock" in the class
name and "mock_" in the header filename.

Fake classes implement a working version of the interface they provide,
often with extra functionality to change their behavior. Those classes
should be prefixed with "Fake" in the class name and "fake_" in the
file name.

Other minor include order fixes are included in this patch.

BUG=None
TEST=Unittest still pass.

Change-Id: I23de7cb11e25182d5855afacca47d431c97b82bb
Reviewed-on: https://chromium-review.googlesource.com/227779
Reviewed-by: Alex Deymo <deymo@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
Tested-by: Alex Deymo <deymo@chromium.org>
diff --git a/mock_prefs.h b/mock_prefs.h
new file mode 100644
index 0000000..176176b
--- /dev/null
+++ b/mock_prefs.h
@@ -0,0 +1,34 @@
+// Copyright (c) 2012 The Chromium OS 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 UPDATE_ENGINE_MOCK_PREFS_H_
+#define UPDATE_ENGINE_MOCK_PREFS_H_
+
+#include <string>
+
+#include <gmock/gmock.h>
+
+#include "update_engine/constants.h"
+#include "update_engine/prefs_interface.h"
+
+namespace chromeos_update_engine {
+
+class MockPrefs : public PrefsInterface {
+ public:
+  MOCK_METHOD2(GetString, bool(const std::string& key, std::string* value));
+  MOCK_METHOD2(SetString, bool(const std::string& key,
+                               const std::string& value));
+  MOCK_METHOD2(GetInt64, bool(const std::string& key, int64_t* value));
+  MOCK_METHOD2(SetInt64, bool(const std::string& key, const int64_t value));
+
+  MOCK_METHOD2(GetBoolean, bool(const std::string& key, bool* value));
+  MOCK_METHOD2(SetBoolean, bool(const std::string& key, const bool value));
+
+  MOCK_METHOD1(Exists, bool(const std::string& key));
+  MOCK_METHOD1(Delete, bool(const std::string& key));
+};
+
+}  // namespace chromeos_update_engine
+
+#endif  // UPDATE_ENGINE_MOCK_PREFS_H_