[ObjC ARC] Converts ios/chrome/test/earl_grey:ios_chrome_device_check_egtests to ARC.
The automatic arc script doesn't work for this target because it simply
adds configs += [ "//build/config/compiler:enable_arc" ] to
chrome_ios_eg_test("ios_chrome_device_check_egtests"), however, the
body of a template invocation doesn't take configs.
This CL manually moves "device_check_egtest.mm" to a separate
source_set and adds configs += [ "//build/config/compiler:enable_arc" ]
to that source_set.
Notable issues:None
BUG=624363
TEST=None
Review-Url: https://codereview.chromium.org/2882253002
Cr-Commit-Position: refs/heads/master@{#472430}
3 files changed
