Remove unused API.

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

Index: dart/sdk/lib/_internal/compiler/implementation/closure.dart
diff --git a/dart/sdk/lib/_internal/compiler/implementation/closure.dart b/dart/sdk/lib/_internal/compiler/implementation/closure.dart
index 11529b6cf7756d91fba9e23add635955bd5051bd..2b0849402d20b22f767e7bcf383771021a762cb3 100644
--- a/dart/sdk/lib/_internal/compiler/implementation/closure.dart
+++ b/dart/sdk/lib/_internal/compiler/implementation/closure.dart
@@ -197,23 +197,6 @@ class ThisElement extends ElementX {
   accept(ElementVisitor visitor) => visitor.visitThisElement(this);
 }
 
-// TODO(ahe): These classes continuously cause problems.  We need to
-// move these classes to elements/modelx.dart or see if we can find a
-// more general solution.
-class CheckVariableElement extends ElementX {
-  Element parameter;
-  CheckVariableElement(String name, this.parameter, Element enclosing)
-      : super(name, ElementKind.VARIABLE, enclosing);
-
-  DartType computeType(Compiler compiler) => compiler.types.dynamicType;
-
-  // Since there is no declaration for the synthetic 'check' variable, use
-  // parameter.
-  Token position() => parameter.position();
-
-  accept(ElementVisitor visitor) => visitor.visitCheckVariableElement(this);
-}
-
 // The box-element for a scope, and the captured variables that need to be
 // stored in the box.
 class ClosureScope {
@@ -271,11 +254,6 @@ class ClosureClassMap {
 
   bool isClosure() => closureElement != null;
 
-  bool isVariableCaptured(Element element) {
-    return freeVariableMapping.containsKey(element)
-        || capturingScopesBox(element);
-  }
-
   bool capturingScopesBox(Element element) {
     return capturingScopes.values.any((scope) {
       return scope.boxedLoopVariables.contains(element);
@@ -307,14 +285,6 @@ class ClosureClassMap {
       scope.capturedVariableMapping.forEach(f);
     });
   }
-
-  void forEachNonBoxedCapturedVariable(void f(Element local, Element field)) {
-    freeVariableMapping.forEach((variable, copy) {
-      if (variable is BoxElement) return;
-      if (isVariableBoxed(variable)) return;
-      f(variable, copy);
-    });
-  }
 }
 
 class ClosureTranslator extends Visitor {