Fix hangs in Mandoline page cycler on Linux with --enable-multiprocess.

components/html_viewer/html_document_application_delegate.h

Index: components/html_viewer/html_document_application_delegate.h
diff --git a/components/html_viewer/html_document_application_delegate.h b/components/html_viewer/html_document_application_delegate.h
index 6b2d3796ab1d29694ce49ca9bd8e5e38933b17c5..8347fb34f29d379a28717d030791153d1c1627eb 100644
--- a/components/html_viewer/html_document_application_delegate.h
+++ b/components/html_viewer/html_document_application_delegate.h
@@ -29,7 +29,8 @@ class HTMLDocumentApplicationDelegate : public mojo::ApplicationDelegate,
       mojo::InterfaceRequest<mojo::Application> request,
       mojo::URLResponsePtr response,
       GlobalState* global_state,
-      scoped_ptr<mojo::AppRefCount> parent_app_refcount);
+      scoped_ptr<mojo::AppRefCount> parent_app_refcount,
+      const mojo::Callback<void()>& destruct_callback);
 
   void set_html_factory(HTMLFactory* factory) { html_factory_ = factory; }
   HTMLFactory* html_factory() { return html_factory_; }
@@ -76,6 +77,8 @@ class HTMLDocumentApplicationDelegate : public mojo::ApplicationDelegate,
 
   HTMLFactory* html_factory_;
 
+  mojo::Callback<void()> destruct_callback_;
+
   base::WeakPtrFactory<HTMLDocumentApplicationDelegate> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HTMLDocumentApplicationDelegate);