update_engine: Switch to chrome-dbus for client requests in update_engine

update_engine daemon acts as DBus client to send DBus calls to shill,
power_manager and chrome, and to listen for signals from shill, chrome
and login_manager. This patch migrates these calls and signals to use
chrome-dbus framework instead of dbus-glib.

All references to dbus-glib code are removed.

BUG=chromium:419827
TEST=Updated unittest. Deployed on a link device and tested interactions with shill and chromium.

Change-Id: I31b389e0d1690cccb115ff3b6539c876ba81bd0e
Reviewed-on: https://chromium-review.googlesource.com/290990
Tested-by: Alex Deymo <deymo@chromium.org>
Reviewed-by: Alex Deymo <deymo@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
Trybot-Ready: Alex Deymo <deymo@chromium.org>
diff --git a/fake_shill_proxy.h b/fake_shill_proxy.h
new file mode 100644
index 0000000..a60e996
--- /dev/null
+++ b/fake_shill_proxy.h
@@ -0,0 +1,54 @@
+// Copyright 2015 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_FAKE_SHILL_PROXY_H_
+#define UPDATE_ENGINE_FAKE_SHILL_PROXY_H_
+
+#include <map>
+#include <memory>
+#include <string>
+
+#include <base/macros.h>
+
+#include "update_engine/dbus_mocks.h"
+#include "update_engine/dbus_proxies.h"
+#include "update_engine/shill_proxy_interface.h"
+
+namespace chromeos_update_engine {
+
+// This class implements the connection to shill using real DBus calls.
+class FakeShillProxy : public ShillProxyInterface {
+ public:
+  FakeShillProxy();
+  ~FakeShillProxy() override = default;
+
+  // ShillProxyInterface overrides.
+
+  // GetManagerProxy returns the subclass ManagerProxyMock so tests can easily
+  // use it. Mocks for the return value of GetServiceForPath() can be provided
+  // with SetServiceForPath().
+  org::chromium::flimflam::ManagerProxyMock* GetManagerProxy() override;
+  std::unique_ptr<org::chromium::flimflam::ServiceProxyInterface>
+  GetServiceForPath(const std::string& path) override;
+
+  // Sets the service_proxy that will be returned by GetServiceForPath().
+  void SetServiceForPath(
+      const std::string& path,
+      std::unique_ptr<org::chromium::flimflam::ServiceProxyInterface>
+          service_proxy);
+
+ private:
+  std::unique_ptr<org::chromium::flimflam::ManagerProxyMock>
+      manager_proxy_mock_;
+
+  std::map<std::string,
+           std::unique_ptr<org::chromium::flimflam::ServiceProxyInterface>>
+      service_proxy_mocks_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeShillProxy);
+};
+
+}  // namespace chromeos_update_engine
+
+#endif  // UPDATE_ENGINE_FAKE_SHILL_PROXY_H_