metrics: add session_manager-client dependency.

In CL:731364 metrics added session_manager-client dependency. This CL
added the dependency at ebuild file as well.

BUG=chromium:776919, chromium:774036
TEST=emerge-lakitu chromeos-base/metrics

Change-Id: I119df265a2cb35a979e63797a7f802fdcd91a87b
Reviewed-on: https://chromium-review.googlesource.com/737773
Tested-by: Chih-Yu Huang <akahuang@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Sergey Poromov <poromov@chromium.org>
Commit-Queue: Chih-Yu Huang <akahuang@chromium.org>
1 file changed