make `SharedOptionsOptionsMap` private

Change-Id: I21bf7f48af568626ded1aa0b885c02b92c514a9f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/350344
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Phil Quitslund <pquitslund@google.com>
diff --git a/pkg/analyzer/lib/src/dart/analysis/analysis_options_map.dart b/pkg/analyzer/lib/src/dart/analysis/analysis_options_map.dart
index d13b464..d8ef881 100644
--- a/pkg/analyzer/lib/src/dart/analysis/analysis_options_map.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/analysis_options_map.dart
@@ -17,6 +17,12 @@
   /// Create an empty [AnalysisOptionsMap] instance.
   AnalysisOptionsMap();
 
+  /// Create an [AnalysisOptionsMap] that holds one set of [sharedOptions] for
+  /// all associated files.
+  factory AnalysisOptionsMap.forSharedOptions(
+          AnalysisOptionsImpl sharedOptions) =>
+      _SharedOptionsOptionsMap(sharedOptions);
+
   /// Get the first options entry or the default options object if there is none.
   AnalysisOptionsImpl get firstOrDefault =>
       entries.firstOrNull?.options ?? _defaultOptions;
@@ -29,7 +35,8 @@
   }
 
   /// Get the [AnalysisOptions] instance for the given [file] (or a shared empty
-  /// default options object if there is no entry in [entries] for a containing folder).
+  /// default options object if there is no entry in [entries] for a containing
+  /// folder).
   AnalysisOptionsImpl getOptions(File file) {
     for (var entry in entries) {
       if (entry.folder.contains(file.path)) return entry.options;
@@ -37,13 +44,6 @@
 
     return _defaultOptions;
   }
-
-  /// Create an [AnalysisOptionsMap] that holds one set of [sharedOptions] for all
-  /// associated files.
-  // TODO(pq): replace w/ a factory constructor when SharedOptionsOptionsMap is made private
-  static SharedOptionsOptionsMap forSharedOptions(
-          AnalysisOptionsImpl sharedOptions) =>
-      SharedOptionsOptionsMap(sharedOptions);
 }
 
 /// Instances of [OptionsMapEntry] associate [Folder]s with their
@@ -59,10 +59,10 @@
   OptionsMapEntry(this.folder, this.options);
 }
 
-// TODO(pq): make private when no longer referenced.
-class SharedOptionsOptionsMap extends AnalysisOptionsMap {
+/// An option map that contains only one shared set of options.
+class _SharedOptionsOptionsMap extends AnalysisOptionsMap {
   final AnalysisOptionsImpl sharedOptions;
-  SharedOptionsOptionsMap(this.sharedOptions) {
+  _SharedOptionsOptionsMap(this.sharedOptions) {
     var optionsFile = sharedOptions.file;
     // If there's an associated file, create an entry so that we can display it
     // in the diagnostics page.