GitLab

See go/closure-compile-gn for details.

This CL removes all remaining traces of GYP Closure Compilation. This
includes:
- all compiled_resources2.gyp files from ui/webui
- all PRESUBMITs that add the closure_compilation bot
- the closure_compilation bot in all build systems
- some GYP tooling that is only used for closure compilation builders

TBR=sashab@chromium.org

Bug: 632206
Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: Ief58c91d43ed859d5b4022dd30e7d5507dd7909b
Reviewed-on: https://chromium-review.googlesource.com/1051144
Commit-Queue: calamity <calamity@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576368}