Let the users skip the gold plugin installation

Let the users skip the gold plugin installation

BUG=None
R=thakis@chromium.org
TEST=local run

[Alexander Potapenko, 2017-03-14 15:01:53]

Hi Nico,

I'm using update.py to fetch the Clang which I then use to build the Linux
kernel (see https://github.com/ramosian-glider/clang-kernel-build)
However this broke recently because update.py depends on the script in the
Chromium directory now.
I'd love an opportunity to simply skip the gold plugin installation phase, as I
don't need the plugin, but if you have better suggestions, I can consider them.

[Nico, 2017-03-14 15:04:31]

Bleh, I forgot that external folks use this script too.

agrieve, can we just revert your patch that downloads this unconditionally?
krasin's actively working on moving the linux official build to lld, and once
that's done we won't need this file at all anymore.

[agrieve, 2017-03-14 15:46:09]

On 2017/03/14 15:04:31, Nico wrote:
> Bleh, I forgot that external folks use this script too.
> 
> agrieve, can we just revert your patch that downloads this unconditionally?
> krasin's actively working on moving the linux official build to lld, and once
> that's done we won't need this file at all anymore.

Sure: https://codereview.chromium.org/2748973003/

[Alexander Potapenko, 2017-03-14 16:55:21]

On 2017/03/14 15:04:31, Nico wrote:
> Bleh, I forgot that external folks use this script too.
Perhaps it is worth a comment at the top of the file? :)
> agrieve, can we just revert your patch that downloads this unconditionally?
> krasin's actively working on moving the linux official build to lld, and once
> that's done we won't need this file at all anymore.

Thanks!

[Derek Schuff, 2017-03-14 19:05:20]

On 2017/03/14 16:55:21, Alexander Potapenko wrote:
> On 2017/03/14 15:04:31, Nico wrote:
> > Bleh, I forgot that external folks use this script too.
> Perhaps it is worth a comment at the top of the file? :)
> > agrieve, can we just revert your patch that downloads this unconditionally?
> > krasin's actively working on moving the linux official build to lld, and
once
> > that's done we won't need this file at all anymore.
> 
> Thanks!

Just an extra +1. We use this for WebAssembly toolchain waterfalls too,  and on
my plate today was going to be figuring out how to work around and/or add this
same option. So thanks!