Add GN isolate support for a bunch of unittests.

This enables the following tests to be run under
swarming on a GN bot:

- angle_unittests
- accessibility_unittests
- compositor_unittests
- cc_unittests
- ipc_tests
- gl_unittests
- sandbox_linux_unittests
- gn_unittests
- skia_unittests
- sql_unittests
- url_unittests

R=brettw@chromium.org, maruel@chromium.org
BUG=504079
CQ_EXTRA_TRYBOTS=tryserver.chromium.mac:mac_chromium_gn_rel

Review URL: https://codereview.chromium.org/1248673005

Cr-Original-Commit-Position: refs/heads/master@{#339973}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 177c1e29c1abeb267b3ab1283a4c7c03a398ec6f
1 file changed
tree: d307c0bd97b161d6d909a57d2ebe6b856c435f8f
  1. tools/