Use memory source files in compile_from_dill*

pkg/compiler/lib/src/library_loader.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js.library_loader;
 
 import 'dart:async';
 
 import 'package:front_end/front_end.dart' as fe;
 import 'package:kernel/ast.dart' as ir;
@@ skipping 806 matching lines @@
 /// A loader that builds a kernel IR representation of the program (or set of
 /// libraries).
 ///
 /// It supports loading both .dart source files or pre-compiled .dill files.
 /// When given .dart source files, it invokes the shared frontend
 /// (`package:front_end`) to produce the corresponding kernel IR representation.
 // TODO(sigmund): move this class to a new file under src/kernel/.
 class KernelLibraryLoaderTask extends CompilerTask
     implements LibraryLoaderTask {
   final Uri sdkRoot;
+  final Uri _packageConfig;
 
   final DiagnosticReporter reporter;
 
   final api.CompilerInput compilerInput;
 
   /// Holds the mapping of Kernel IR to KElements that is constructed as a
   /// result of loading a program.
   final KernelToElementMapForImpactImpl _elementMap;
 
   List<LibraryEntity> _allLoadedLibraries;
 
-  KernelLibraryLoaderTask(this.sdkRoot, this._elementMap, this.compilerInput,
-      this.reporter, Measurer measurer)
+  KernelLibraryLoaderTask(this.sdkRoot, this._packageConfig, this._elementMap,
+      this.compilerInput, this.reporter, Measurer measurer)
       : _allLoadedLibraries = new List<LibraryEntity>(),
         super(measurer);
 
   /// Loads an entire Kernel [Program] from a file on disk (note, not just a
   /// library, so this name is actually a bit of a misnomer).
   // TODO(efortuna): Rename this once the Element library loader class goes
   // away.
   Future<LoadedLibraries> loadLibrary(Uri resolvedUri,
       {bool skipFileWithPartOfTag: false}) {
     return measure(() async {
       var isDill = resolvedUri.path.endsWith('.dill');
       ir.Program program;
       if (isDill) {
         api.Input input = await compilerInput.readFromUri(resolvedUri,
             inputKind: api.InputKind.binary);
         program = new ir.Program();
         new BinaryBuilder(input.data).readProgram(program);
       } else {
         var options = new fe.CompilerOptions()
           ..fileSystem = new CompilerFileSystem(compilerInput)
           ..target = new Dart2jsTarget(new TargetFlags())
           ..linkedDependencies = [
             sdkRoot.resolve('_internal/dart2js_platform.dill')
           ]
+          ..packagesFileUri = _packageConfig
           ..onError = (e) => reportFrontEndMessage(reporter, e);
 
         program = await fe.kernelForProgram(resolvedUri, options);
       }
       if (program == null) return null;
       return createLoadedLibraries(program);
     });
   }
 
   // Only visible for unit testing.
@@ skipping 838 matching lines @@
 }
 
 /// API used by the library loader to synchronously scan a library or
 /// compilation unit and ensure that their library tags are computed.
 abstract class ElementScanner {
   void scanLibrary(LibraryElement library);
   void scanUnit(CompilationUnitElement unit);
 }
 
 const _reuseLibrarySubtaskName = "Reuse library";