Move webrtc/{tools => rtc_tools}

webrtc/tools/header_usage.sh

-#!/bin/bash
-
-# Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
-#
-# Use of this source code is governed by a BSD-style license
-# that can be found in the LICENSE file in the root of the source
-# tree. An additional intellectual property rights grant can be found
-# in the file PATENTS.  All contributing project authors may
-# be found in the AUTHORS file in the root of the source tree.
-
-# This script is run in a git repository. It lists all header files,
-# sorted by the number of other files where the file name of the file
-# occurs. It is intentionally not limited to only source files, and
-# there may be some false hits because we search only for the file
-# part (sans directory). It is quite slow.
-#
-# Headers close to the top of the list are candidates for removal.
-
-git ls-files '*.h' '*.hpp' | while read header ; do
-  name="$(basename "${header}")"
-  count="$(git grep -l -F  "${name}" \
-           | grep -v -e '\.gn' -e '\.gyp'  \
-           | wc -l)"
-  echo "${count}" "${header}"
-done | sort -n