For ios, only compile the necessary parts of //ipc.

Until recently ios didn't use //ipc but //services/network
needs some small parts of them. Some of the rest of the ipc
code won't even link in ios since ios has no
discarding some unused object files before noticing they referenced
non-existing symbols.

base: :WaitableEventWatcher. It's built so far thanks to the linker
Change-Id: Ieaf3749e1b4f0d8f46f652248b839ae9e8650282
Reviewed-on: https://chromium-review.googlesource.com/c/1273498
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#601218}
1 file changed