libchromeos: Switch ExportedObjectManager to use DBusObject

Use DBusObject helper class to implement D-Bus object for
ExportedObjectManager.

Now that Variant data type serialization on D-Bus is supported,
switch a number of method handler to be a higher-level C++
callbacks that return native data types which can automatically
be sent over D-Bus with the help of AppendValueToWriter() functions.

Removed remaining scoped_ptr in dbus_utils and dbus_object
and replaced them with std::unique_ptr.

BUG=None
TEST=FEATURES=test emerge-link libchromeos
     USE=buffet P2_TEST_FILTER="buffet::*" FEATURES=test emerge-link platform2

Change-Id: I53bdb5301ec6c3460873c5ac1559fb5d171850a4
Reviewed-on: https://chromium-review.googlesource.com/213963
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
3 files changed
tree: 3da7bae7ad3aa080b9572589b6d583f9de6c262c
  1. buffet/