Unbreak closure invocation name minification.

sdk/lib/_internal/compiler/implementation/universe/universe.dart

Index: sdk/lib/_internal/compiler/implementation/universe/universe.dart
diff --git a/sdk/lib/_internal/compiler/implementation/universe/universe.dart b/sdk/lib/_internal/compiler/implementation/universe/universe.dart
index 02a0b8287213b5ccd3f170f02c78f0027009d030..2cd54a6d522c9aa55233858639bf1d564cece1db 100644
--- a/sdk/lib/_internal/compiler/implementation/universe/universe.dart
+++ b/sdk/lib/_internal/compiler/implementation/universe/universe.dart
@@ -226,10 +226,6 @@ class Selector {
   /** Check whether this is a call to 'assert'. */
   bool isAssert() => isCall() && identical(name.stringValue, "assert");
 
-  /** Check whether this is a closure invocation call. */
-  bool isClosureCall() =>
-      isCall() && identical(name.stringValue, Compiler.CALL_OPERATOR_NAME);
-
   int get hashCode => argumentCount + 1000 * namedArguments.length;
   int get namedArgumentCount => namedArguments.length;
   int get positionalArgumentCount => argumentCount - namedArgumentCount;