Infer types for parameters even in the presence of InvocationMirror.delegate.

sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/js_backend/backend.dart	(revision 29416)
+++ sdk/lib/_internal/compiler/implementation/js_backend/backend.dart	(working copy)
@@ -424,7 +424,6 @@
 
   bool invokedReflectively(Element element) {
     if (element.isParameter() || element.isFieldParameter()) {
-      if (hasInsufficientMirrorsUsed && compiler.enabledInvokeOn) return true;
       if (invokedReflectively(element.enclosingElement)) return true;
     }
 
@@ -433,7 +432,6 @@
           && (element.modifiers.isFinal() || element.modifiers.isConst())) {
         return false;
       }
-      if (hasInsufficientMirrorsUsed && compiler.enabledInvokeOn) return true;
     }
 
     return isNeededForReflection(element.declaration);