Elements. Deprecate TopLevelVariableElement.

Change-Id: Ifb1a5f5454cdc1e67c512a68196a5ff5ccf549e2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/418911
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Paul Berry <[email protected]>

Author: scheglov

pkg/analyzer/api.txt

@@ -3495,7 +3495,7 @@ package:analyzer/dart/element/element.dart:
   SuperFormalParameterElement (class extends Object implements ParameterElement):
     new (constructor: SuperFormalParameterElement Function())
     superConstructorParameter (getter: ParameterElement?)
-  TopLevelVariableElement (class extends Object implements PropertyInducingElement):
+  TopLevelVariableElement (class extends Object implements PropertyInducingElement, deprecated):
     new (constructor: TopLevelVariableElement Function())
     declaration (getter: TopLevelVariableElement)
     isExternal (getter: bool)

pkg/analyzer/lib/dart/element/element.dart

@@ -2175,6 +2175,7 @@ abstract class SuperFormalParameterElement implements ParameterElement {
 /// A top-level variable.
 ///
 /// Clients may not extend, implement or mix-in this class.
+@Deprecated('Use TopLevelVariableElement2 instead')
 abstract class TopLevelVariableElement implements PropertyInducingElement {
   @override
   TopLevelVariableElement get declaration;

pkg/analyzer/lib/src/dart/element/element.dart

@@ -1762,8 +1762,6 @@ mixin ConstructorElementMixin2
   InterfaceTypeImpl get returnType;
 }
 
-/// A [TopLevelVariableElement] for a top-level 'const' variable that has an
-/// initializer.
 class ConstTopLevelVariableElementImpl extends TopLevelVariableElementImpl
     with ConstVariableElement {
   /// Initialize a newly created synthetic top-level variable element to have
@@ -10859,9 +10857,11 @@ class TopLevelFunctionFragmentImpl extends FunctionElementImpl
   }
 }
 
-/// A concrete implementation of a [TopLevelVariableElement].
 class TopLevelVariableElementImpl extends PropertyInducingElementImpl
-    implements TopLevelVariableElement, TopLevelVariableFragment {
+    implements
+        // ignore:deprecated_member_use_from_same_package
+        TopLevelVariableElement,
+        TopLevelVariableFragment {
   @override
   late TopLevelVariableElementImpl2 element;
 

pkg/analyzer/lib/src/utilities/extensions/element.dart

@@ -670,18 +670,6 @@ extension TopLevelFunctionElementImplExtension on TopLevelFunctionElementImpl {
   }
 }
 
-extension TopLevelVariableElement2Extension on TopLevelVariableElement2 {
-  TopLevelVariableElement get asElement {
-    return baseElement.firstFragment as TopLevelVariableElement;
-  }
-}
-
-extension TopLevelVariableElementExtension on TopLevelVariableElement {
-  TopLevelVariableElement2 get asElement2 {
-    return (this as TopLevelVariableElementImpl).element;
-  }
-}
-
 extension TopLevelVariableElementImpl2Extension
     on TopLevelVariableElementImpl2 {
   TopLevelVariableElementImpl get asElement {