No-compile tests have been disabled for a while on GYP build, and GN
didn't support it.
This CL converts //build/nocompile.gypi to //build/nocompile.gni to
support no-compile test, and splits out test cases from base_unittests
to base_nocompile_tests on GN build.
This doesn't enable the test by default. To opt-in to it, set
enable_nocompile_tests to true in GN args.
BUG=568478
Review URL: https://codereview.chromium.org/1526933002
Cr-Original-Commit-Position: refs/heads/master@{#365757}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 0137dc5d4031d8bc13d28adf579a9af6a2169c75
tzik