analyzer: Use Workspace.partialSourceFactory in more places

For better caching.

Change-Id: Ia5c9df85169731ae256dfe68cfe54115a9b402f3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/489540
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
Auto-Submit: Samuel Rawlins <srawlins@google.com>

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

@@ -247,8 +247,7 @@ class ContextBuilderImpl {
     );
 
     {
-      // TODO(scheglov): We already had partial SourceFactory in ContextLocatorImpl.
-      var partialSourceFactory = workspace.createSourceFactory(null, null);
+      var partialSourceFactory = workspace.partialSourceFactory;
       var embedderYamlSource = partialSourceFactory.forUri(
         'package:sky_engine/_embedder.yaml',
       );

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

@@ -242,7 +242,9 @@ class _ContextLocator {
     required _RootLocation location,
   }) {
     if (location.workspace is WorkspaceWithDefaultAnalysisOptions) {
-      optionsFile ??= _findDefaultOptionsFile(location.sourceFactory);
+      optionsFile ??= _findDefaultOptionsFile(
+        location.workspace.partialSourceFactory,
+      );
     }
 
     var root = ContextRootImpl(
@@ -257,7 +259,7 @@ class _ContextLocator {
     }
 
     root.excludedGlobs.addAll(
-      _getExcludedGlobs(optionsFile, location.sourceFactory),
+      _getExcludedGlobs(optionsFile, location.workspace.partialSourceFactory),
     );
     roots.add(root);
     return root;
@@ -918,9 +920,6 @@ class _RootLocation {
   final File? optionsFile;
   final File? packageConfigFile;
 
-  /// A single source factory for [workspace].
-  late final sourceFactory = workspace.createSourceFactory(null, null);
-
   _RootLocation({
     required this.rootFolder,
     required this.workspace,