Revert of Enable Control Flow Integrity for the official Linux Chrome. (patchset #3 id:40001 of https://codereview.chromium.org/1513623004/ )

Reason for revert:
Link time for the official Chrome on the perf buildbot is more than 1 hour. Possibly, some regression in LLVM Gold plugin.

Original issue's description:
> Enable Control Flow Integrity for the official Linux Chrome.
>
> This CL turns on CFI, a security check:
> https://sites.google.com/a/chromium.org/dev/developers/testing/control-flow-integrity
> http://clang.llvm.org/docs/ControlFlowIntegrity.html
>
> This feature enables LTO (Link-Time Optimization) builds, which slow down the linker by 3x-4x.
> CFI also comes with a code size overhead of about 7%-9%. The runtime CPU cost is less than 1%,
> and should not be an issue.
>
> BUG=chromium:464797
> Intent to Implement thread:
> https://groups.google.com/a/chromium.org/d/msg/chromium-dev/pbJqt6ccMII/7iJC2oklCAAJ
>
> This is a fifth attempt to land the CL. Previous attempts:
> https://codereview.chromium.org/1502373003/
> https://codereview.chromium.org/1501593003/
> https://codereview.chromium.org/1393283005/
> https://codereview.chromium.org/1502233004/
>
> The last time it failed, it was primarily due to the new Clang roll,
> that had a bug in the linker. This is now fixed upstream and
> the new Clang roll happened: https://crbug.com/568248
>
> Perf bots were purple and got a RAM upgrade: https://crbug.com/567787
>
> precice64 official buildbot got OOM due to too many Gold instances
> running in parallel: https://crbug.com/568011, a more conservative
> limit was submitted: https://codereview.chromium.org/1509733004/
>
> TBR=thestig@chromium.org
>
> Committed: https://crrev.com/efe55ae0c0f26165d71d540ac319ccc9bc569cb3
> Cr-Commit-Position: refs/heads/master@{#365117}

TBR=thakis@chromium.org,thestig@chromium.org,phajdan.jr@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:464797

Review URL: https://codereview.chromium.org/1530553002

Cr-Commit-Position: refs/heads/master@{#365133}
3 files changed