Remove most of the remaining references to AnalysisContext

pkg/analysis_server/lib/src/services/refactoring/rename_import.dart

Index: pkg/analysis_server/lib/src/services/refactoring/rename_import.dart
diff --git a/pkg/analysis_server/lib/src/services/refactoring/rename_import.dart b/pkg/analysis_server/lib/src/services/refactoring/rename_import.dart
index 1f5ef92b0c04aae762168eb33bef5d6e133e9306..38ffe36ea7999913ebc5f13c7f5d85ddb815816a 100644
--- a/pkg/analysis_server/lib/src/services/refactoring/rename_import.dart
+++ b/pkg/analysis_server/lib/src/services/refactoring/rename_import.dart
@@ -85,7 +85,7 @@ class RenameImportRefactoringImpl extends RenameRefactoringImpl {
         reference.addEdit(change, '');
       } else {
         SimpleIdentifier interpolationIdentifier =
-            _getInterpolationIdentifier(reference);
+            await _getInterpolationIdentifier(reference);
         if (interpolationIdentifier != null) {
           doSourceChange_addElementEdit(
               change,
@@ -116,9 +116,12 @@ class RenameImportRefactoringImpl extends RenameRefactoringImpl {
    * an [InterpolationExpression] without surrounding curly brackets, return it.
    * Otherwise return `null`.
    */
-  SimpleIdentifier _getInterpolationIdentifier(SourceReference reference) {
+  Future<SimpleIdentifier> _getInterpolationIdentifier(
+      SourceReference reference) async {
     Source source = reference.element.source;
-    CompilationUnit unit = context.parseCompilationUnit(source);
+    CompilationUnit unit =
+        (await astProvider.driver.currentSession.getParsedAst(source.fullName))

[scheglov, 2017/08/23 19:27:28]

Ideally I would prefer to put each `await` into a separate statement.
Especially in long statements.

Also here I'd extract `currentSession` into a local variable.

[Brian Wilkerson, 2017/08/23 19:56:52]

Done

+            .unit;
     NodeLocator nodeLocator = new NodeLocator(reference.range.offset);
     AstNode node = nodeLocator.searchWithin(unit);
     if (node is SimpleIdentifier) {