Revert "Reapply "Enable full type-checks in checked mode.""

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

Index: sdk/lib/_internal/compiler/implementation/dart_types.dart
diff --git a/sdk/lib/_internal/compiler/implementation/dart_types.dart b/sdk/lib/_internal/compiler/implementation/dart_types.dart
index ecee2ba0a21f362a9597705684b6836750e0f523..6f76fe64a4428268717040a82b7c05940215522f 100644
--- a/sdk/lib/_internal/compiler/implementation/dart_types.dart
+++ b/sdk/lib/_internal/compiler/implementation/dart_types.dart
@@ -118,8 +118,6 @@ abstract class DartType {
    */
   TypeVariableType get typeVariableOccurrence => null;
 
-  void forEachTypeVariable(f(TypeVariableType variable)) {}
-
   TypeVariableType _findTypeVariableOccurrence(Link<DartType> types) {
     for (Link<DartType> link = types; !link.isEmpty ; link = link.tail) {
       TypeVariableType typeVariable = link.head.typeVariableOccurrence;
@@ -205,10 +203,6 @@ class TypeVariableType extends DartType {
 
   DartType get typeVariableOccurrence => this;
 
-  void forEachTypeVariable(f(TypeVariableType variable)) {
-    f(this);
-  }
-
   accept(DartTypeVisitor visitor, var argument) {
     return visitor.visitTypeVariableType(this, argument);
   }
@@ -413,12 +407,6 @@ abstract class GenericType extends DartType {
     return _findTypeVariableOccurrence(typeArguments);
   }
 
-  void forEachTypeVariable(f(TypeVariableType variable)) {
-    for (Link<DartType> link = typeArguments; !link.isEmpty; link = link.tail) {
-      link.head.forEachTypeVariable(f);
-    }
-  }
-
   void visitChildren(DartTypeVisitor visitor, var argument) {
     DartType.visitList(typeArguments, visitor, argument);
   }