Make landmines work on local builds too

Moves (some of) gyp environment setup out of gyp_chromium into separate
module, and shares that between gyp_chromium and landmines.py.

landmines.py is added as the first entry in DEPS hooks so that it can
clobber the entire build directory before running other hooks that
extract/generate into the build dir.

Reland with fix for ios, and for clean pull.

R=iannucci@chromium.org
BUG=400011

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=289099

Review URL: https://codereview.chromium.org/457003004

Cr-Commit-Position: refs/heads/master@{#289546}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289546 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: 9372becb96814e31181d143ecbcef57c38ccea2b
4 files changed
tree: 1f305c7a6a1d1e5a0086d5a84f3a9f82d68f1052
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/