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

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

Index: sdk/lib/_internal/compiler/implementation/closure.dart
diff --git a/sdk/lib/_internal/compiler/implementation/closure.dart b/sdk/lib/_internal/compiler/implementation/closure.dart
index fff0b379a9f566126ad8960642af2cf25550bdb5..b9b83e2bb716db19122e95b3bf1800e4a6cf4a11 100644
--- a/sdk/lib/_internal/compiler/implementation/closure.dart
+++ b/sdk/lib/_internal/compiler/implementation/closure.dart
@@ -390,20 +390,11 @@ class ClosureTranslator extends Visitor {
     scopeVariables.add(element);
   }
 
-  void registerNeedsThis() {
-    if (closureData.thisElement != null) {
-      useLocal(closureData.thisElement);
-    }
-  }
-
   visit(Node node) => node.accept(this);
 
   visitNode(Node node) => node.visitChildren(this);
 
   visitVariableDefinitions(VariableDefinitions node) {
-    if (node.type != null) {
-      visit(node.type);
-    }
     for (Link<Node> link = node.definitions.nodes;
          !link.isEmpty;
          link = link.tail) {
@@ -426,38 +417,13 @@ class ClosureTranslator extends Visitor {
     }
   }
 
-  visitTypeAnnotation(TypeAnnotation node) {
-    Element member = currentElement.getEnclosingMember();
-    DartType type = elements.getType(node);
-    // TODO(karlklose,johnniwinther): if the type is null, the annotation is
-    // from a parameter which has been analyzed before the method has been
-    // resolved and the result has been thrown away.
-    if (compiler.enableTypeAssertions && type != null &&
-        type.containsTypeVariables) {
-      if (insideClosure && member.isFactoryConstructor()) {
-        // This is a closure in a factory constructor.  Since there is no
-        // [:this:], we have to mark the type arguments as free variables to
-        // capture them in the closure.
-        type.forEachTypeVariable((variable) => useLocal(variable.element));
-      }
-      // TODO(karlklose): try to get rid of the isField check; there is a bug
-      // with type variable use in field initializer (in both modes).
-      if (member.isInstanceMember() && !member.isField()) {
-        // In checked mode, using a type variable in a type annotation may lead
-        // to a runtime type check that needs to access the type argument and
-        // therefore the closure needs a this-element.
-        registerNeedsThis();
-      }
-    }
-  }
-
   visitIdentifier(Identifier node) {
     if (node.isThis()) {
-      registerNeedsThis();
+      useLocal(closureData.thisElement);
     } else {
       Element element = elements[node];
       if (element != null && element.kind == ElementKind.TYPE_VARIABLE) {
-        registerNeedsThis();
+        useLocal(closureData.thisElement);
       }
     }
     node.visitChildren(this);
@@ -469,9 +435,9 @@ class ClosureTranslator extends Visitor {
       useLocal(element);
     } else if (node.receiver == null &&
                Elements.isInstanceSend(node, elements)) {
-      registerNeedsThis();
+      useLocal(closureData.thisElement);
     } else if (node.isSuperCall) {
-      registerNeedsThis();
+      useLocal(closureData.thisElement);
     } else if (node.isParameterCheck) {
       Element parameter = elements[node.receiver];
       FunctionElement enclosing = parameter.enclosingElement;
@@ -495,10 +461,6 @@ class ClosureTranslator extends Visitor {
     if (Elements.isLocal(element)) {
       mutatedVariables.add(element);
     }
-    if (Elements.isLocal(element) &&
-        element.computeType(compiler).containsTypeVariables) {
-      registerNeedsThis();
-    }
     super.visitSendSet(node);
   }
 
@@ -535,9 +497,7 @@ class ClosureTranslator extends Visitor {
       if (outermostElement.isConstructor() || outermostElement.isField()) {
         analyzeTypeVariables(type);
       } else if (outermostElement.isInstanceMember()) {
-        if (hasTypeVariable(type)) {
-          registerNeedsThis();
-        }
+        if (hasTypeVariable(type)) useLocal(closureData.thisElement);
       }
     }
 
@@ -709,12 +669,6 @@ class ClosureTranslator extends Visitor {
         });
       }
 
-      // Compute the function type and check for type variables in return or
-      // parameter types.
-      if (element.computeType(compiler).containsTypeVariables) {
-        registerNeedsThis();
-      }
-
       visitChildren();
     });