Revert of Created an empty expectations file to ignore flaky tests (patchset...

Revert of Created an empty expectations file to ignore flaky tests (patchset #9 id:160001 of https://codereview.chromium.org/376653002/)

Reason for revert:
Ignorer-bot project has been delayed to determine whether it is necessary at all. This doesn't have to be in the repo.

Original issue's description:
> Created an empty expectations file to ignore flaky tests
>
> This is used by https://codereview.chromium.org/373223003/
>
> BUG=390600
> R=eseidel@chromium.org, stip@chromium.org, hinoka@chromium.org
>
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=284062

TBR=ojan@chromium.org,eseidel@chromium.org,hinoka@chromium.org,sergeyberezin@chromium.org,stip@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=390600

Review URL: https://codereview.chromium.org/549103003

Cr-Commit-Position: refs/heads/master@{#293750}

tools/ignorer_bot/ignored_failed_tests.txt

-# THIS FILE IS GENERATED AUTOMATICALLY BY IGNORER-BOT. PLEASE DO NOT EDIT.
-#
-# This file contains a list of ignored failed tests. Each line that starts with
-# a hash (#) or empty is ignored. Other lines are parsed by the test runner to
-# ignore failures of specified tests on particular platforms. Each such line has
-# the following format:
-#
-#   crbug.com/ISSUE [ PLATFORM1, PLATFORM2, ... ] TESTNAME
-#
-# where
-#  - ISSUE is the id of the associated issue for the flaky test;
-#  - PLATFORM1, PLATFORM2 etc. are each formated as a list of platform flags
-#    separated by whitespace, e.g. "OS_WIN CPU_32_BITS MODE_RELEASE" and limit
-#    on which platforms the test is disabled (note that square brackets and
-#    commas are part of the syntax and do NOT denote this section as optional);
-#  - TESTNAME is a name of the test to be ignored.