Teach the analyzer about dart:sky.internals.

sky/sdk/lib/internals.dart

Index: sky/sdk/lib/internals.dart
diff --git a/sky/sdk/lib/internals.dart b/sky/sdk/lib/internals.dart
index 4a0b207942b1d1fc002ec378929c63f5d68d9c45..e30aa1d37c5fd821e0de697b8870348faf20b240 100644
--- a/sky/sdk/lib/internals.dart
+++ b/sky/sdk/lib/internals.dart
@@ -4,5 +4,11 @@
 
 library sky.internals;
 
-int takeServicesProvidedByEmbedder() native "takeServicesProvidedByEmbedder";
+String contentAsText() native "contentAsText";
+String renderTreeAsText() native "renderTreeAsText";
+void notifyTestComplete(String test_result) native "notifyTestComplete";
 
+int takeShellProxyHandle() native "takeShellProxyHandle";
+int takeServicesProvidedByEmbedder() native "takeServicesProvidedByEmbedder";
+int takeServicesProvidedToEmbedder() native "takeServicesProvidedToEmbedder";
+int takeServiceRegistry() native "takeServiceRegistry";