With this change, in the Chromium repo NaCl will now be built solely using Chromium's versions of the GN build files, rather than a mixture of chromium and NaCl files.
This will allow us to delete the NaCl versions in a subsequent NaCl-side CL and switch to pulling the chromium versions in via a DEPS entry, and thus "unfork" the build.
R=brettw@chromium.org, ncbray@chromium.org, mcgrathr@chromium.org
BUG=433528
Review URL: https://codereview.chromium.org/1312813003
Cr-Original-Commit-Position: refs/heads/master@{#346452}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: fa6ffe2fb9f488ddb859555f5abc29de72407a62
3d822fcafd