DevTools: move protocol-related generators into inspector subfolder.

BUG=580337
NOPRESUBMIT=true

Review URL: https://codereview.chromium.org/1696513002

Cr-Original-Commit-Position: refs/heads/master@{#375109}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: b4b1bdc22eabec57d57b92968a4fbf882446dfda
5 files changed