Move webrtc/{tools => rtc_tools}

webrtc/rtc_tools/testing/README.md

 This directory contains prebuilt tools used during end-to-end tests.
 They will be downloaded by their SHA1 hash, and are not meant to be checked in.
 
 Updating prebuilt_apprtc.zip:
 
 - Follow AppRTC instructions:
     - `git clone https://github.com/webrtc/apprtc`
     - Install NodeJS:
         - Download <https://nodejs.org/> and extract it
         - `export PATH="$(pwd)/node-v6.10.3-linux-x64/bin:$PATH"`
     - `cd apprtc`
     - `npm install`
     - `export PATH="$(pwd)/node_modules/.bin:$PATH"`
     - `pip install --user --upgrade pip setuptools` - needed only on old systems
     - `grunt`
 - Vendor collider's dependencies:
     - `ln -s "$(pwd)/src/collider" src/src`
     - `GOPATH="$(pwd)/src" go get -d collidermain`
     - `rm src/src`
 - Remove unneeded files:
     - `rm -rf .git node_modules browsers`
 - `zip -r prebuilt_apprtc.zip apprtc/`
-- `mv prebuilt_apprtc.zip webrtc/src/webrtc/tools/testing/prebuilt_apprtc.zip`
+- `mv prebuilt_apprtc.zip webrtc/src/webrtc/rtc_tools/testing/prebuilt_apprtc.zip`
 
 Updating golang/*:
 
 - Go to <https://golang.org/dl/>
 - Download these files:
     - go*.linux-amd64.tar.gz -> golang/linux/go.tar.gz
     - go*.darwin-amd64.tar.gz -> golang/mac/go.tar.gz
     - go*.windows-amd64.zip -> golang/windows/go.zip
 
 After updating the archives:
 
-- `cd webrtc/src/webrtc/tools/testing`
+- `cd webrtc/src/webrtc/rtc_tools/testing`
 - For each updated archive:
     - `upload_to_google_storage.py file.zip --bucket=chromium-webrtc-resources`
 - `git commit -a && git cl upload`