Update power_Consumption autotest to use CloseTab instead of TabProxy.Close()

TEST=power_Consumption
BUG=chromium:132789

Change-Id: I29bfe14cb85d581e8d1056980ec59d4af932ee1c
Reviewed-on: https://gerrit.chromium.org/gerrit/29382
Reviewed-by: Nirnimesh <nirnimesh@chromium.org>
Commit-Ready: Craig Harrison <craigdh@chromium.org>
Tested-by: Craig Harrison <craigdh@chromium.org>
1 file changed