Eliminate usage of InterfacePtr::WaitForIncomingResponse.

mash/catalog_viewer/catalog_viewer.cc

Index: mash/catalog_viewer/catalog_viewer.cc
diff --git a/mash/catalog_viewer/catalog_viewer.cc b/mash/catalog_viewer/catalog_viewer.cc
index 0aa4a241fa477e579a2d1354207957f586a8b4c9..fcb162e321d18f8f4d2b2839be15c001d5e4bc85 100644
--- a/mash/catalog_viewer/catalog_viewer.cc
+++ b/mash/catalog_viewer/catalog_viewer.cc
@@ -50,12 +50,12 @@ class CatalogViewerContents : public views::WidgetDelegateView,
     table_view_parent_ = table_view_->CreateParentIfNecessary();
     AddChildView(table_view_parent_);
 
-    catalog_->GetEntries(nullptr,
-                         base::Bind(&CatalogViewerContents::OnGotCatalogEntries,
-                                    weak_ptr_factory_.GetWeakPtr()));
     // We don't want to show an empty UI so we just block until we have all the
-    // data.
-    catalog_.WaitForIncomingResponse();
+    // data. GetEntries is a sync call.
+    mojo::Array<catalog::mojom::EntryPtr> entries;
+    catalog_->GetEntries(nullptr, &entries);
+
+    OnGotCatalogEntries(entries);
   }
   ~CatalogViewerContents() override {
     table_view_->SetModel(nullptr);
@@ -117,7 +117,8 @@ class CatalogViewerContents : public views::WidgetDelegateView,
     observer_ = observer;
   }
 
-  void OnGotCatalogEntries(mojo::Array<catalog::mojom::EntryPtr> entries) {
+  void OnGotCatalogEntries(
+      const mojo::Array<catalog::mojom::EntryPtr>& entries) {
     entries_.clear();
     for (auto& entry : entries)
       entries_.push_back(Entry(entry->display_name, entry->name));