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

components/html_viewer/content_handler_impl.cc

Index: components/html_viewer/content_handler_impl.cc
diff --git a/components/html_viewer/content_handler_impl.cc b/components/html_viewer/content_handler_impl.cc
index 3d1a8a34790eddd75e2220a0ffb0912c68e284a4..0b3b2ef93112f36914ef9bd80d831efe31e2426b 100644
--- a/components/html_viewer/content_handler_impl.cc
+++ b/components/html_viewer/content_handler_impl.cc
@@ -12,12 +12,12 @@ namespace html_viewer {
 
 ContentHandlerImpl::ContentHandlerImpl(
     GlobalState* global_state,
-    mojo::ApplicationImpl* app,
+    mojo::Shell* shell,
     mojo::InterfaceRequest<mojo::shell::mojom::ContentHandler> request)
     : global_state_(global_state),
-      app_(app),
+      shell_(shell),
       binding_(this, std::move(request)),
-      app_refcount_(app_->app_lifetime_helper()->CreateAppRefCount()) {}
+      app_refcount_(shell_->CreateAppRefCount()) {}
 
 ContentHandlerImpl::~ContentHandlerImpl() {
 }
@@ -29,7 +29,7 @@ void ContentHandlerImpl::StartApplication(
   // HTMLDocumentApplicationDelegate deletes itself.
   new HTMLDocumentApplicationDelegate(
       std::move(request), std::move(response), global_state_,
-      app_->app_lifetime_helper()->CreateAppRefCount(), destruct_callback);
+      shell_->CreateAppRefCount(), destruct_callback);
 }
 
 }  // namespace html_viewer