Move webrtc/{tools => rtc_tools}

webrtc/rtc_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