GitLab

Currently, ObjectProxy::CallMethodAndBlock() returns NULL on
failure but the D-Bus error details are not passed to the caller.

Added a method that would return the D-Bus error information
to the caller and switched ObjectProxy::CallMethodAndBlock()
to use the new method instead.

BUG=chromium:414838
TEST=Build Chrome
TEST=ninja -C out/Debug dbus_unittests && out/Debug/dbus_unittests

Review URL: https://codereview.chromium.org/563763004

Cr-Commit-Position: refs/heads/master@{#295212}