[element model] migrate driver

Change-Id: Ie4d18ec4188cb3a5d2fbb1059f8988f4e4310ea8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/403705
Commit-Queue: Phil Quitslund <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: pq

pkg/analyzer/analyzer_use_new_elements.txt

@@ -9,7 +9,6 @@ lib/dart/element/type_provider.dart
 lib/dart/element/type_system.dart
 lib/dart/element/visitor.dart
 lib/error/listener.dart
-lib/src/dart/analysis/driver.dart
 lib/src/dart/analysis/index.dart
 lib/src/dart/analysis/library_analyzer.dart
 lib/src/dart/analysis/library_context.dart

pkg/analyzer/lib/src/dart/analysis/driver.dart

@@ -597,7 +597,7 @@ class AnalysisDriver {
       var uriStr = uri.toString();
       var libraryResult = await getLibraryByUri(uriStr);
       if (libraryResult is LibraryElementResult) {
-        var libraryElement = libraryResult.element as LibraryElementImpl;
+        var libraryElement = libraryResult.element2 as LibraryElementImpl;
         bundleWriter.writeLibraryElement(libraryElement);
 
         packageBundleBuilder.addLibrary(
@@ -894,7 +894,7 @@ class AnalysisDriver {
     if (_pendingFileChanges.isEmpty) {
       var rootReference = libraryContext.elementFactory.rootReference;
       var reference = rootReference.getChild('$uriObj');
-      var element = reference.element;
+      var element = reference.element2;
       if (element is LibraryElementImpl) {
         return LibraryElementResultImpl(element);
       }