remove unused DDC --package-paths options and MultiPackageResolver

pkg/dev_compiler/lib/src/analyzer/context.dart

Index: pkg/dev_compiler/lib/src/analyzer/context.dart
diff --git a/pkg/dev_compiler/lib/src/analyzer/context.dart b/pkg/dev_compiler/lib/src/analyzer/context.dart
index 5617f7fe4c8be5630b656c4d0c52962c05fbabef..d2bfe96286640100b2269fd74900b4340288ddaf 100644
--- a/pkg/dev_compiler/lib/src/analyzer/context.dart
+++ b/pkg/dev_compiler/lib/src/analyzer/context.dart
@@ -22,8 +22,6 @@ import 'package:analyzer/src/summary/summary_sdk.dart' show SummaryBasedDartSdk;
 import 'package:cli_util/cli_util.dart' show getSdkDir;
 import 'package:path/path.dart' as path;
 
-import 'multi_package_resolver.dart' show MultiPackageResolver;
-
 /// Options used to set up Source URI resolution in the analysis context.
 class AnalyzerOptions {
   /// Custom URI mappings, such as "dart:foo" -> "path/to/foo.dart"
@@ -35,9 +33,6 @@ class AnalyzerOptions {
   /// List of summary file paths.
   final List<String> summaryPaths;
 
-  /// List of paths used for the multi-package resolver.
-  final List<String> packagePaths;
-
   /// Path to the dart-sdk. Null if `useMockSdk` is true or if the path couldn't
   /// be determined
   final String dartSdkPath;
@@ -55,7 +50,6 @@ class AnalyzerOptions {
       this.dartSdkSummaryPath,
       this.customUrlMappings: const {},
       this.packageRoot: null,
-      this.packagePaths: const [],
       this.declaredVariables: const {}})
       : dartSdkPath = dartSdkPath ?? getSdkDir().path;
 
@@ -77,13 +71,9 @@ class AnalyzerOptions {
         dartSdkSummaryPath: sdkSummaryPath,
         customUrlMappings: _parseUrlMappings(args['url-mapping']),
         packageRoot: args['package-root'],
-        packagePaths: (args['package-paths'] as String)?.split(',') ?? [],
         declaredVariables: declaredVariables);
   }
 
-  /// Whether to resolve 'package:' uris using the multi-package resolver.
-  bool get useMultiPackage => packagePaths.isNotEmpty;
-
   static void addArguments(ArgParser parser) {
     parser
       ..addOption('summary',
@@ -98,9 +88,7 @@ class AnalyzerOptions {
           help: '--url-mapping=libraryUri,/path/to/library.dart uses\n'
               'library.dart as the source for an import of of "libraryUri".',
           allowMultiple: true,
-          splitCommas: false)
-      ..addOption('package-paths',
-          help: 'use a list of directories to resolve "package:" imports');
+          splitCommas: false);
   }
 
   static Map<String, String> _parseUrlMappings(Iterable argument) {
@@ -168,12 +156,7 @@ List<UriResolver> createFileResolvers(AnalyzerOptions options,
         builder.convertPackagesToMap(builder.createPackageMap('')));
   }
 
-  return [
-    new ResourceUriResolver(resourceProvider),
-    options.useMultiPackage
-        ? new MultiPackageResolver(options.packagePaths)
-        : packageResolver()
-  ];
+  return [new ResourceUriResolver(resourceProvider), packageResolver()];
 }
 
 FolderBasedDartSdk _createFolderBasedDartSdk(String sdkPath) {