Rename the PolicyManager to UpdateManager.

This change renames the PolicyManager class, directory, tests, etc,
to avoid confusion with libpolicy and its classes.

BUG=chromium:373551
TEST=emerged on link.
CQ-DEPEND=CL:I43081673c7ba409f02273197da7915537bde39c6

Change-Id: Iffa76caa3b95ecbbdba87ab01006d1d8ce35a27f
Reviewed-on: https://chromium-review.googlesource.com/201876
Tested-by: Alex Deymo <deymo@chromium.org>
Reviewed-by: David Zeuthen <zeuthen@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
diff --git a/update_manager/update_manager.cc b/update_manager/update_manager.cc
new file mode 100644
index 0000000..d3281fd
--- /dev/null
+++ b/update_manager/update_manager.cc
@@ -0,0 +1,20 @@
+// Copyright (c) 2014 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.
+
+#include "update_engine/update_manager/update_manager.h"
+
+#include "update_engine/update_manager/chromeos_policy.h"
+#include "update_engine/update_manager/state.h"
+
+namespace chromeos_update_manager {
+
+UpdateManager::UpdateManager(chromeos_update_engine::ClockInterface* clock,
+                             State* state)
+      : state_(state), clock_(clock) {
+  // TODO(deymo): Make it possible to replace this policy with a different
+  // implementation with a build-time flag.
+  policy_.reset(new ChromeOSPolicy());
+}
+
+}  // namespace chromeos_update_manager