Removed DARTIUM codegen for IDLS (sdk/lib/dartium)

tools/dom/templates/html/impl/impl_CompositionEvent.darttemplate

Index: tools/dom/templates/html/impl/impl_CompositionEvent.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_CompositionEvent.darttemplate b/tools/dom/templates/html/impl/impl_CompositionEvent.darttemplate
index 5b3d3914e4198fb7580c197dd65c95900b769c3c..f3da2dbd12559de530cbfe523c9e7cfe8d800862 100644
--- a/tools/dom/templates/html/impl/impl_CompositionEvent.darttemplate
+++ b/tools/dom/templates/html/impl/impl_CompositionEvent.darttemplate
@@ -15,7 +15,6 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
     }
     CompositionEvent e = document._createEvent("CompositionEvent");
 
-$if DART2JS
     if (Device.isFirefox) {
       // Firefox requires the locale parameter that isn't supported elsewhere.
       JS('void', '#.initCompositionEvent(#, #, #, #, #, #)',
@@ -23,9 +22,6 @@ $if DART2JS
     } else {
       e._initCompositionEvent(type, canBubble, cancelable, view, data);
     }
-$else
-      e._initCompositionEvent(type, canBubble, cancelable, view, data);
-$endif
 
     return e;
   }