[reland] Do not set default wallpaper unless it should do so.

TBR=bshe@chromium.org, alemate@chromium.org

Bug: 751382
Change-Id: Id0793dfe467f737526a95b1e66ed01fbb8860bda
Reviewed-on: https://chromium-review.googlesource.com/619754
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Reviewed-by: Biao She <bshe@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#498325}
Reviewed-on: https://chromium-review.googlesource.com/646430
Cr-Commit-Position: refs/heads/master@{#498982}
void WallpaperManager::Open() {
  if (wallpaper_manager_util::ShouldUseAndroidWallpapersApp(
          ProfileHelper::Get()->GetProfileByUser(
              user_manager::UserManager::Get()->GetActiveUser())) &&
      !ash_util::IsRunningInMash()) {
    activation_client_observer_.Add(ash::Shell::Get()->activation_client());
  }
  wallpaper_manager_util::OpenWallpaperManager();
}

void WallpaperManager::Open() {
  if (wallpaper_manager_util::ShouldUseAndroidWallpapersApp(
          ProfileHelper::Get()->GetProfileByUser(
              user_manager::UserManager::Get()->GetActiveUser())) &&
      !ash_util::IsRunningInMash()) {
    activation_client_observer_.Add(ash::Shell::Get()->activation_client());
  }
  wallpaper_manager_util::OpenWallpaperManager();
}
