Use precompiled dependencies in pub.

sdk/lib/_internal/pub/lib/src/barback/transformers_needed_by_transformers.dart

Index: sdk/lib/_internal/pub/lib/src/barback/transformers_needed_by_transformers.dart
diff --git a/sdk/lib/_internal/pub/lib/src/barback/transformers_needed_by_transformers.dart b/sdk/lib/_internal/pub/lib/src/barback/transformers_needed_by_transformers.dart
index c9cfdafc58baf0fafd3573df962fe938dfd4cc48..e32b42b6efc594bdff0dd0a9bc57a771c0372a5b 100644
--- a/sdk/lib/_internal/pub/lib/src/barback/transformers_needed_by_transformers.dart
+++ b/sdk/lib/_internal/pub/lib/src/barback/transformers_needed_by_transformers.dart
@@ -11,7 +11,6 @@ import '../io.dart';
 import '../package.dart';
 import '../package_graph.dart';
 import '../utils.dart';
-import 'asset_environment.dart';
 import 'cycle_exception.dart';
 import 'transformer_config.dart';
 import 'transformer_id.dart';
@@ -26,16 +25,11 @@ import 'transformer_id.dart';
 /// The returned graph is transitively closed. That is, if there's an edge from
 /// `T1` to `T2` and an edge from `T2` to `T3`, there's also an edge from `T1`
 /// to `T2`.
-///
-/// If [packages] is passed, only transformers in those packages will be
-/// inspected.
 Map<TransformerId, Set<TransformerId>> computeTransformersNeededByTransformers(
-    PackageGraph graph, {Iterable<String> packages}) {
-  if (packages == null) packages = graph.packages.keys;
-
+    PackageGraph graph) {
   var result = {};
   var computer = new _DependencyComputer(graph);
-  for (var packageName in ordered(packages)) {
+  for (var packageName in ordered(graph.packages.keys)) {
     var package = graph.packages[packageName];
     for (var phase in package.pubspec.transformers) {
       for (var config in phase) {
@@ -102,7 +96,7 @@ class _DependencyComputer {
           '"$packageUri").');
     }
 
-    var library = p.join(package.dir, 'lib', p.joinAll(components.skip(1)));
+    var library = package.path('lib', p.joinAll(components.skip(1)));
 
     _loadPackageComputer(packageName);
     return _packageComputers[packageName].transformersNeededByLibrary(library);
@@ -241,7 +235,7 @@ class _PackageDependencyComputer {
             // set that would be recomputed if [transformersNeededByLibrary]
             // were called anew.
             _transformersNeededByTransformers[id] =
-                transformersNeededByLibrary(id.getFullPath(_package.dir));
+                transformersNeededByLibrary(_package.transformerPath(id));
           }
         } on CycleException catch (error) {
           throw error.prependStep("$packageName is transformed by $id");
@@ -267,7 +261,7 @@ class _PackageDependencyComputer {
     }
 
     _transformersNeededByTransformers[id] =
-        transformersNeededByLibrary(id.getFullPath(_package.dir));
+        transformersNeededByLibrary(_package.transformerPath(id));
     return _transformersNeededByTransformers[id];
   }
 
@@ -353,7 +347,7 @@ class _PackageDependencyComputer {
             continue;
           }
 
-          path = p.join(_package.dir, 'lib', p.joinAll(components.skip(1)));
+          path = _package.path('lib', p.joinAll(components.skip(1)));
         } else if (uri.scheme == '' || uri.scheme == 'file') {
           path = p.join(p.dirname(library), p.fromUri(uri));
         } else {
@@ -377,7 +371,7 @@ class _PackageDependencyComputer {
   /// If [library] is modified by a transformer, this will return `null`.
   Set<Uri> _getDirectives(String library) {
     var libraryUri = p.toUri(p.normalize(library));
-    var relative = p.toUri(p.relative(library, from: _package.dir)).path;
+    var relative = p.toUri(_package.relative(library)).path;
     if (_applicableTransformers.any((config) =>
             config.canTransform(relative))) {
       _directives[libraryUri] = null;