Force jumbo builds to fail.

We no longer have any builders supporting the jumbo build config,
and it's time to now update all of the build files to remove
the jumbo templates. Before we do that, though, it's probably good
to figure out how to handle existing uses of the jumbo builds.

This CL asserts that |use_jumbo_build| is set to false. Once
we've run with this for a while (to ensure that people have
adjusted their configs), we can probably update any CI build
configs to remove the use of it and the other jumbo-related GN
args and then remove the actual declare_args() of the three
jumbo args, turning uses of them into warnings.

Bug: 994387
Change-Id: Ibe395e51c837692ff9a7b6d01141c32ddab5459b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1874583
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
Reviewed-by: Aaron Gable <agable@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710481}
7 files changed