Revert of Sandbox html_viewer on Linux. (patchset chromium#6 id:10000…

…1 of https://codereview.chromium.org/1274743004/ )

Reason for revert:
Doesn't build on the Linux GN bot: http://build.chromium.org/p/chromium.linux/builders/Linux%20GN/builds/30188/steps/compile/logs/stdio

Original issue's description:
> Sandbox html_viewer on Linux.
>
> This creates a font_service which does the same role as
> font_config_ipc_linux.cc does in content/. This lets us sandbox the
> html_viewer, while still being able to communicate with fontconfig.
>
> Also prewarms the ICU timezone data, along with doing all the
> prewarming that's done in the core_services sandbox.
>
> BUG=492524
> NOPRESUBMIT=true
>
> Committed: https://crrev.com/4196dfefc131b0a77a3e02e917b852dba8faf445
> Cr-Commit-Position: refs/heads/master@{#342281}

TBR=jam@chromium.org,erg@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=492524

Review URL: https://codereview.chromium.org/1276163002

Cr-Commit-Position: refs/heads/master@{#342286}