Redo normal expressions in dialog updater to be thread-safe

plugins/org.chromium.debug.ui/src/org/chromium/debug/ui/WizardUtils.java

Index: plugins/org.chromium.debug.ui/src/org/chromium/debug/ui/WizardUtils.java
diff --git a/plugins/org.chromium.debug.ui/src/org/chromium/debug/ui/WizardUtils.java b/plugins/org.chromium.debug.ui/src/org/chromium/debug/ui/WizardUtils.java
index 0224208af4fabbe50442876db7e1133f972a5f57..d5835449fd984ec1b0e7a0bb9f9fed5b20655909 100644
--- a/plugins/org.chromium.debug.ui/src/org/chromium/debug/ui/WizardUtils.java
+++ b/plugins/org.chromium.debug.ui/src/org/chromium/debug/ui/WizardUtils.java
@@ -280,12 +280,12 @@ public class WizardUtils {
    */
   public static class WizardFinishController implements ValueConsumer {
     private final ValueSource<? extends Optional<? extends WizardFinisher>> finisherValue;
-    private final ValueSource<? extends Optional<Void>> warningValue;
+    private final ValueSource<? extends Optional<?>> warningValue;
     private final LogicBasedWizard wizardImpl;
 
     public WizardFinishController(
         ValueSource<? extends Optional<? extends WizardFinisher>> finisherValue,
-        ValueSource<? extends Optional<Void>> warningValue,
+        ValueSource<? extends Optional<? extends Void>> warningValue,
         LogicBasedWizard wizardImpl) {
       this.finisherValue = finisherValue;
       this.warningValue = warningValue;
@@ -296,7 +296,7 @@ public class WizardUtils {
       WizardFinisher finisher;
       Set<Message> messages = new HashSet<Message>();
       if (warningValue != null) {
-        Optional<Void> warnings = warningValue.getValue();
+        Optional<?> warnings = warningValue.getValue();
         if (!warnings.isNormal()) {
           messages.addAll(warnings.errorMessages());
         }