Revert of mac: Sign app_mode_loader [badly] (patchset #1 id:1 of https://codereview.chromium.org/1486863003/ )
Revert of mac: Sign app_mode_loader [badly] (patchset #1 id:1 of https://codereview.chromium.org/1486863003/ )

Reason for revert:
Suspected for breaking official signing, see https://code.google.com/p/chromium/issues/detail?id=565859

Original issue's description:
> mac: Sign app_mode_loader [badly]
>
> We can't sign the app_mode_loader bundle because it's altered at runtime
> as new app mode loader stubs are created. We can sign just the
> executable. The resulting executable won't validate in its bundle
> normally, and spctl won't like it, but it can be verified with
> --ignore-resources, or in isolation from its bundle.
>
> BUG=550972
>
> Committed: https://crrev.com/2720613d5ea1db967ac883fcc9282ec60ad1ddd5
> Cr-Commit-Position: refs/heads/master@{#363070}

TBR=kerrnel@chromium.org,mark@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=550972, 565859

Review URL: https://codereview.chromium.org/1491213009

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#363179}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk