Define "invalid".

The bot looks to be happily running builds:
https://ci.chromium.org/buildbot/chromium.android/Android%20Cronet%20Builder%20Asan/

And clang is the default compiler for android (and has been for a while now IIUC).

Nothing is wrong with the builder itself, just the spec in chromium_tests. None of the trybots refer to it and attempting to call configure_build with a BotConfig for that spec results in an exception because clang and default_compiler are both part of the "compiler" group and the recipe engine won't allow multiple items from the same group to be applied.

In https://cs.chromium.org/chromium/build/scripts/slave/recipe_modules/chromium_tests/tests/builders.py, if you comment out the entry from the blacklist, you get the following error:
BadConf: config "chromium_asan" includes "clang", but ["clang" is a member of group "compiler", but ('default_compiler',) already ran]

Alright, it prob just needs a config tweak. I'll do that.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build/+/aad7bb07e3037bde5b271d6343eda73245e382e2

commit aad7bb07e3037bde5b271d6343eda73245e382e2
Author: Ben Pastene <bpastene@chromium.org>
Date: Thu Jun 21 22:46:47 2018

Fix Android Cronet Builder Asan's compile recipe config.

Bug:  853899 
Change-Id: Ia591b2fc5d1d3fd55b31397496b129a0fe7eb2a6
Reviewed-on: https://chromium-review.googlesource.com/1109272
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>

[modify] https://crrev.com/aad7bb07e3037bde5b271d6343eda73245e382e2/scripts/slave/recipe_modules/chromium_tests/chromium_android.py
[modify] https://crrev.com/aad7bb07e3037bde5b271d6343eda73245e382e2/scripts/slave/recipe_modules/chromium_tests/tests/builders.py