Drop --enable-encrypted-media flag.
Drop --enable-encrypted-media flag.

Prefixed EME is supported in chrome by default. Unprefixed EME is disabled by
default and can be enabled with --enable-encrytped-media flag. On ChromeOS
devices we should not enable unprefixed EME for now.

For the Chrome side change, see: http://codereview.chromium.org/12090061

BUG=chromium:254759
TEST=none

Change-Id: Ia7fdf97efff3f072e1c0718b7e86477635108153
Reviewed-on: https://gerrit.chromium.org/gerrit/60171
Reviewed-by: David Dorwin <7285fc8420ade15dc45c0d23efd2156d30510c16@chromium.org>
Commit-Queue: Xiaohan Wang <bb381fe471dcc258176d423b112ac22ee2549723@chromium.org>
Reviewed-by: Xiaohan Wang <bb381fe471dcc258176d423b112ac22ee2549723@chromium.org>
Tested-by: Xiaohan Wang <bb381fe471dcc258176d423b112ac22ee2549723@chromium.org>

chadversary/chromiumos.platform.login_manager,chadversary/chromiumos.platform.login_manager,chadversary/chromiumos.platform.login_manager