Allow isolated_app to talk to webviewupdate_service.

It's okay for isolated apps to connect to the webview update service to
find out which APK is WebView. This enables isolated renderer processes
to load their code from the WebView APK.

Change-Id: Ia287280a994dbd852b4f630da5548e7b6cf4e08f
diff --git a/isolated_app.te b/isolated_app.te
index c27b547..6497cf1 100644
--- a/isolated_app.te
+++ b/isolated_app.te
@@ -17,6 +17,7 @@
 
 allow isolated_app activity_service:service_manager find;
 allow isolated_app display_service:service_manager find;
+allow isolated_app webviewupdate_service:service_manager find;
 
 # Google Breakpad (crash reporter for Chrome) relies on ptrace
 # functionality. Without the ability to ptrace, the crash reporter
@@ -40,12 +41,13 @@
 neverallow isolated_app app_data_file:file open;
 
 # b/17487348
-# Isolated apps can only access two services,
-# activity_service and display_service
+# Isolated apps can only access three services,
+# activity_service, display_service and webviewupdate_service.
 neverallow isolated_app {
     service_manager_type
     -activity_service
     -display_service
+    -webviewupdate_service
 }:service_manager find;
 
 # Isolated apps shouldn't be able to access the driver directly.