Reland #2 of Add GN build rules to allow java_assertion_enabler to enable Java asserts.

Reverted by:
https://codereview.chromium.org/2506263003/

Reason for reland:
Fixed failing tests.

TBR=jbudorick@chromium.org,agrieve@chromium.org,toyoshim@chromium.org,qinmin@chromium.org,yolandyan@chromium.org
BUG=666193,667337,462676,665157,665478,667437

Review-Url: https://codereview.chromium.org/2517203002
Cr-Commit-Position: refs/heads/master@{#433681}
10 files changed