Revert of Validate origins when generating subdomain tokens (patchset #12 id:240001 of https://codereview.chromium.org/2456053004/ )

Reason for revert:
Breaks official Android builds, see https://bugs.chromium.org/p/chromium/issues/detail?id=676894

Original issue's description:
> Validate origins when generating subdomain tokens
>
> Subdomain tokens will match against any subdomains of the given origin.
> This relaxed matching should not be applied when subdomains represent
> separate logical sites (e.g. <user>.github.io). Thus, subdomain tokens
> are not to be issued for such domains. For more detail, see the last
> question in the Origin Trials developer guide:
> https://github.com/jpchase/OriginTrials/blob/gh-pages/developer-guide.md
>
> This CL adds a utility to validate that a origin is not found in the
> Public Suffix List. The token generation script will now call the
> utility to check the origin, only for subdomain tokens. The utility
> is used when the generation script is manually run by the origin
> trials team to issue tokens. The intent is to automate the origin
> checks, to reduce the number of manual steps in issuing tokens.
>
> BUG=658856
>
> Committed: https://crrev.com/6205808cb4e9c61264e4aa48676e2f5833a61326
> Cr-Commit-Position: refs/heads/master@{#440554}

TBR=iclelland@chromium.org,agrieve@chromium.org,rdsmith@chromium.org,rsleevi@chromium.org,brettw@chromium.org,chasej@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=658856

Review-Url: https://codereview.chromium.org/2605563003
Cr-Original-Commit-Position: refs/heads/master@{#440670}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 14e7a72edd0b2d0b313d047e33069cebc76cc0ab

config/linux/gconf/BUILD.gn

@@ -8,6 +8,11 @@ import("//build/config/linux/pkg_config.gni")
 # CrOS doesn't install GTK, gconf or any gnome packages.
 assert(!is_chromeos && use_gconf)
 
+# These packages should _only_ be expected when building for a target.
+# If these extra checks are not run, gconf is required when building host
+# tools for a CrOS build.
+assert(current_toolchain == default_toolchain)
+
 pkg_config("gconf") {
   packages = [ "gconf-2.0" ]
   defines = [ "USE_GCONF" ]