Enable jumbo for media/cast

Building //media takes around 23 CPU minutes. A experimental
branch showed that this could be reduced, by using jumbo,
to around 9 CPU minutes. media/cast is the fourth largest part
of media and takes around 2 CPU minutes to compile without
jumbo.

This commit enables jumbo for media/cast.

Bug: 867350
Change-Id: Iaefb6e7ac95c1c7fab78478f879a8ba542f329d9
Reviewed-on: https://chromium-review.googlesource.com/1152807
Reviewed-by: Chrome Cunningham (In Paris) <chcunningham@chromium.org>
Commit-Queue: Chrome Cunningham (In Paris) <chcunningham@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578609}
1 file changed