Add an emacs mode for gn files.

BUG=none

Review URL: https://codereview.chromium.org/1048103003

Cr-Original-Commit-Position: refs/heads/master@{#323075}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 3074045136e6a83a08de513e847c68ccfb71e4dd
2 files changed
tree: 7ffa861a20a862196c02de5c3d7ae31e418db827
  1. tools/