Make test_runner::AppBannerClient an internal detail of components/test_runner.

content/shell/renderer/layout_test/blink_test_runner.h

Index: content/shell/renderer/layout_test/blink_test_runner.h
diff --git a/content/shell/renderer/layout_test/blink_test_runner.h b/content/shell/renderer/layout_test/blink_test_runner.h
index e8d840c3e3ccc77d5e51cf5b54525dc19cf8cabf..3a4e011403b52dc2ef5f8867f8ed92867fc1f333 100644
--- a/content/shell/renderer/layout_test/blink_test_runner.h
+++ b/content/shell/renderer/layout_test/blink_test_runner.h
@@ -153,9 +153,6 @@ class BlinkTestRunner : public RenderViewObserver,
       int request_id,
       const std::vector<std::string>& event_platforms,
       const base::Callback<void(bool)>& callback) override;
-  void ResolveBeforeInstallPromptPromise(
-      int request_id,
-      const std::string& platform) override;
   blink::WebPlugin* CreatePluginPlaceholder(
     blink::WebLocalFrame* frame,
     const blink::WebPluginParams& params) override;