Improve nomenclature of new AnalysisContext async method.

pkg/analysis_server/lib/src/services/completion/dart_completion_manager.dart

Index: pkg/analysis_server/lib/src/services/completion/dart_completion_manager.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/dart_completion_manager.dart b/pkg/analysis_server/lib/src/services/completion/dart_completion_manager.dart
index f20a87721bc0d4351b0f8fb41d77f461fa5e3184..1264d3064a7a561fb418445167236fa8f99ae57c 100644
--- a/pkg/analysis_server/lib/src/services/completion/dart_completion_manager.dart
+++ b/pkg/analysis_server/lib/src/services/completion/dart_completion_manager.dart
@@ -188,7 +188,7 @@ class DartCompletionManager extends CompletionManager {
    * compilation unit is never going to be resolved.
    */
   Future<CompilationUnit> waitForAnalysis() {
-    return context.getResolvedCompilationUnitFuture(
+    return context.computeResolvedCompilationUnitAsync(
         source,
         source).catchError((_) {
       // This source file is not scheduled for analysis, so a resolved