Delete unused / unimplemented methods in digital_goods_impl.

Missed when moved out to util.

Change-Id: I6684b417d869f3ebac6b53c3e549f49b41d1d6da
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2612289
Auto-Submit: Glen Robertson <glenrob@chromium.org>
Commit-Queue: Jeevan Shikaram <jshikaram@chromium.org>
Reviewed-by: Jeevan Shikaram <jshikaram@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842840}

chrome/browser/apps/digital_goods/digital_goods_impl.h

@@ -41,8 +41,6 @@ class DigitalGoodsImpl
   RENDER_DOCUMENT_HOST_USER_DATA_KEY_DECL();
 
   arc::ArcDigitalGoodsBridge* GetArcDigitalGoodsBridge();
-  std::string GetTwaPackageName();
-  std::string GetScope();
 
   content::RenderFrameHost* render_frame_host_;
   mojo::Receiver<payments::mojom::DigitalGoods> receiver_;