Elements. Deprecate LibraryExportElement.

Change-Id: I00d7ded2ef5100702a5989492d731aaf4668d670
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/418923
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Paul Berry <[email protected]>

Author: scheglov

pkg/analyzer/api.txt

@@ -3393,14 +3393,14 @@ package:analyzer/dart/element/element.dart:
     typeSystem (getter: TypeSystem)
     units (getter: List<CompilationUnitElement>, deprecated)
     getClass (method: ClassElement? Function(String), deprecated)
-  LibraryExportElement (class extends Object implements _ExistingElement):
+  LibraryExportElement (class extends Object implements _ExistingElement, deprecated):
     new (constructor: LibraryExportElement Function())
     combinators (getter: List<NamespaceCombinator>)
     enclosingElement3 (getter: CompilationUnitElement, deprecated)
     exportKeywordOffset (getter: int)
     exportedLibrary (getter: LibraryElement?)
     uri (getter: DirectiveUri)
-  LibraryImportElement (class extends Object implements _ExistingElement):
+  LibraryImportElement (class extends Object implements _ExistingElement, deprecated):
     new (constructor: LibraryImportElement Function())
     combinators (getter: List<NamespaceCombinator>)
     enclosingElement3 (getter: CompilationUnitElement, deprecated)

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

@@ -1747,6 +1747,7 @@ abstract class LibraryElement implements _ExistingElement {
 /// A single export directive within a library.
 ///
 /// Clients may not extend, implement or mix-in this class.
+@Deprecated('Use LibraryExport instead')
 abstract class LibraryExportElement implements _ExistingElement {
   /// The combinators that were specified as part of the `export` directive in
   /// the order in which they were specified.
@@ -1769,6 +1770,7 @@ abstract class LibraryExportElement implements _ExistingElement {
 /// A single import directive within a library.
 ///
 /// Clients may not extend, implement or mix-in this class.
+@Deprecated('Use LibraryImport instead')
 abstract class LibraryImportElement implements _ExistingElement {
   /// The combinators that were specified as part of the `import` directive in
   /// the order in which they were specified.

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

@@ -7511,7 +7511,10 @@ class LibraryElementImpl extends ElementImpl
 }
 
 class LibraryExportElementImpl extends _ExistingElementImpl
-    implements LibraryExportElement, LibraryExport {
+    implements
+        // ignore:deprecated_member_use_from_same_package
+        LibraryExportElement,
+        LibraryExport {
   @override
   final List<NamespaceCombinator> combinators;
 
@@ -7571,7 +7574,10 @@ class LibraryExportElementImpl extends _ExistingElementImpl
 }
 
 class LibraryImportElementImpl extends _ExistingElementImpl
-    implements LibraryImportElement, LibraryImport {
+    implements
+        // ignore:deprecated_member_use_from_same_package
+        LibraryImportElement,
+        LibraryImport {
   @override
   final List<NamespaceCombinator> combinators;