Use unions for interface control messages.

mojo/public/tools/bindings/generators/java_templates/interface_definition.tmpl

Index: mojo/public/tools/bindings/generators/java_templates/interface_definition.tmpl
diff --git a/mojo/public/tools/bindings/generators/java_templates/interface_definition.tmpl b/mojo/public/tools/bindings/generators/java_templates/interface_definition.tmpl
index 527e15fbfcf5d6d7581a115f22900715a6076717..c7dcbbc7cbe0bd89bf82d8556eda9daa81001a60 100644
--- a/mojo/public/tools/bindings/generators/java_templates/interface_definition.tmpl
+++ b/mojo/public/tools/bindings/generators/java_templates/interface_definition.tmpl
@@ -91,11 +91,11 @@ try {
     }
     switch(header.getType()) {
 {%   if with_response %}
-        case org.chromium.mojo.bindings.InterfaceControlMessagesConstants.RUN_MESSAGE_ID:
+        case org.chromium.mojo.bindings.interfacecontrol.InterfaceControlMessagesConstants.RUN_MESSAGE_ID:
             return org.chromium.mojo.bindings.InterfaceControlMessagesHelper.handleRun(
                     getCore(), {{interface|name}}_Internal.MANAGER, messageWithHeader, receiver);
 {%   else %}
-        case org.chromium.mojo.bindings.InterfaceControlMessagesConstants.RUN_OR_CLOSE_PIPE_MESSAGE_ID:
+        case org.chromium.mojo.bindings.interfacecontrol.InterfaceControlMessagesConstants.RUN_OR_CLOSE_PIPE_MESSAGE_ID:
             return org.chromium.mojo.bindings.InterfaceControlMessagesHelper.handleRunOrClosePipe(
                     {{interface|name}}_Internal.MANAGER, messageWithHeader);
 {%   endif %}