Remove the chrome_child build artifacts when doing a single DLL build.

This help ensuring that an old version of chrome_child.dll won't be
accidently packaged in the installer.

This code should be removed once we drop support for the multi DLL
build.

Tested manually on a local build.

Bug: 1017245, 726150
Change-Id: I49c3885f937d6b034d94340e23cd83341fc3bd77
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1876232
Commit-Queue: Sébastien Marchand <sebmarchand@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708843}
1 file changed