Remove chromeos-wm from the files that we test for.

With Aura, we won't have a need for the WM any more.

TEST=built an image without chromeos-wm, verified that the build system didn't complain.

Change-Id: Id6e5006770f72ea45f440dbe56ff7f53262864c1
Reviewed-on: https://gerrit.chromium.org/gerrit/15212
Tested-by: Stéphane Marchesin <marcheu@chromium.org>
Reviewed-by: Daniel Erat <derat@chromium.org>
Commit-Ready: Stéphane Marchesin <marcheu@chromium.org>

build_library/test_build_root

@@ -31,7 +31,6 @@ if [[ ! -d "$ROOT" ]]; then
 fi
 
 BINARIES="$ROOT/usr/bin/Xorg
-          $ROOT/usr/bin/chromeos-wm
           $ROOT/boot/vmlinuz
           $ROOT/sbin/session_manager
           $ROOT/bin/sed

build_library/test_image_content.sh

@@ -8,7 +8,6 @@ test_image_content() {
 
   local binaries=(
     "$root/usr/bin/Xorg"
-    "$root/usr/bin/chromeos-wm"
     "$root/boot/vmlinuz"
     "$root/sbin/session_manager"
     "$root/bin/sed"