Revert "Remove unused option in server API"

pkg/analysis_server/lib/src/context_manager.dart

Index: pkg/analysis_server/lib/src/context_manager.dart
diff --git a/pkg/analysis_server/lib/src/context_manager.dart b/pkg/analysis_server/lib/src/context_manager.dart
index c1739b80b0e683464b4fc80c334665e432cae314..66977c472fc347921240701911ff6560bff928c5 100644
--- a/pkg/analysis_server/lib/src/context_manager.dart
+++ b/pkg/analysis_server/lib/src/context_manager.dart
@@ -9,6 +9,7 @@ import 'dart:collection';
 import 'dart:convert';
 import 'dart:core';
 
+import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analyzer/exception/exception.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
@@ -16,8 +17,10 @@ import 'package:analyzer/plugin/options.dart';
 import 'package:analyzer/plugin/resolver_provider.dart';
 import 'package:analyzer/source/analysis_options_provider.dart';
 import 'package:analyzer/source/config.dart';
+import 'package:analyzer/source/package_map_provider.dart';
 import 'package:analyzer/source/package_map_resolver.dart';
 import 'package:analyzer/source/path_filter.dart';
+import 'package:analyzer/source/pub_package_map_provider.dart';
 import 'package:analyzer/source/sdk_ext.dart';
 import 'package:analyzer/src/context/builder.dart';
 import 'package:analyzer/src/context/context.dart' as context;
@@ -331,6 +334,12 @@ abstract class ContextManagerCallbacks {
   void applyChangesToContext(Folder contextFolder, ChangeSet changeSet);
 
   /**
+   * Signals that the context manager has started to compute a package map (if
+   * [computing] is `true`) or has finished (if [computing] is `false`).
+   */
+  void computingPackageMap(bool computing);
+
+  /**
    * Create and return a context builder that can be used to create a context
    * for the files in the given [folder] when analyzed using the given [options].
    */
@@ -446,8 +455,12 @@ class ContextManagerImpl implements ContextManager {
   final ResolverProvider packageResolverProvider;
 
   /**
-   * Provider of analysis options.
+   * Provider which is used to determine the mapping from package name to
+   * package folder.
    */
+  final PubPackageMapProvider _packageMapProvider;
+
+  /// Provider of analysis options.
   AnalysisOptionsProvider analysisOptionsProvider =
       new AnalysisOptionsProvider();
 
@@ -493,6 +506,7 @@ class ContextManagerImpl implements ContextManager {
       this.resourceProvider,
       this.sdkManager,
       this.packageResolverProvider,
+      this._packageMapProvider,
       this.analyzedFilesGlobs,
       this._instrumentationService,
       this.defaultContextOptions) {
@@ -969,19 +983,35 @@ class ContextManagerImpl implements ContextManager {
       // resolve packages.
       return new NoPackageFolderDisposition(packageRoot: packageRoot);
     } else {
-      // Try .packages first.
-      if (absolutePathContext.basename(packagespecFile.path) ==
-          PACKAGE_SPEC_NAME) {
-        Packages packages = _readPackagespec(packagespecFile);
-        return new PackagesFileDisposition(packages);
-      }
-      if (packageResolverProvider != null) {
-        UriResolver resolver = packageResolverProvider(folder);
-        if (resolver != null) {
-          return new CustomPackageResolverDisposition(resolver);
+      PackageMapInfo packageMapInfo;
+      callbacks.computingPackageMap(true);
+      try {
+        // Try .packages first.
+        if (absolutePathContext.basename(packagespecFile.path) ==
+            PACKAGE_SPEC_NAME) {
+          Packages packages = _readPackagespec(packagespecFile);
+          return new PackagesFileDisposition(packages);
         }
+        if (packageResolverProvider != null) {
+          UriResolver resolver = packageResolverProvider(folder);
+          if (resolver != null) {
+            return new CustomPackageResolverDisposition(resolver);
+          }
+        }
+
+        ServerPerformanceStatistics.pub.makeCurrentWhile(() {
+          packageMapInfo = _packageMapProvider.computePackageMap(folder);
+        });
+      } finally {
+        callbacks.computingPackageMap(false);
+      }
+      for (String dependencyPath in packageMapInfo.dependencies) {
+        addDependency(dependencyPath);
+      }
+      if (packageMapInfo.packageMap == null) {
+        return new NoPackageFolderDisposition();
       }
-      return new NoPackageFolderDisposition();
+      return new PackageMapDisposition(packageMapInfo.packageMap);
     }
   }