Extract shell methods from ApplicationImpl into a base class, and pass this to Initialize() instead.

components/html_viewer/global_state.h

Index: components/html_viewer/global_state.h
diff --git a/components/html_viewer/global_state.h b/components/html_viewer/global_state.h
index 73b3e7a17851e79cac6f035f83eaeee516a72285..1017db753e1639bfc0b3e1e04f8d732117ca69ec 100644
--- a/components/html_viewer/global_state.h
+++ b/components/html_viewer/global_state.h
@@ -24,13 +24,8 @@ class FontLoader;
 }
 
 namespace mojo {
-class ApplicationImpl;
-namespace shell {
-namespace mojom {
 class Shell;
 }
-}
-}
 
 namespace ui {
 namespace mojo {
@@ -57,7 +52,7 @@ class MediaFactory;
 // . with a ui: this is done via InitIfNecessary().
 class GlobalState {
  public:
-  explicit GlobalState(mojo::ApplicationImpl* app);
+  GlobalState(mojo::Shell* shell, const std::string& url);
   ~GlobalState();
 
   // Inits with the specified screen size and device pixel ratio.
@@ -102,7 +97,7 @@ class GlobalState {
   // App for HTMLViewer, not the document's app.
   // WARNING: do not expose this. It's too easy to use the wrong one.
   // HTMLDocument should be using the application it creates, not this one.
-  mojo::ApplicationImpl* app_;
+  mojo::Shell* shell_;
 
   resource_provider::ResourceLoader resource_loader_;