Revert "Use native async/await support in pub."

sdk/lib/_internal/pub_generated/lib/src/barback/dependency_computer.dart

Index: sdk/lib/_internal/pub_generated/lib/src/barback/dependency_computer.dart
diff --git a/sdk/lib/_internal/pub/lib/src/barback/dependency_computer.dart b/sdk/lib/_internal/pub_generated/lib/src/barback/dependency_computer.dart
similarity index 94%
copy from sdk/lib/_internal/pub/lib/src/barback/dependency_computer.dart
copy to sdk/lib/_internal/pub_generated/lib/src/barback/dependency_computer.dart
index 0105cbfae020728f3fe777fdcb6992d819d94dba..f9aff0b32234c413872d411281b75ba447a91a2d 100644
--- a/sdk/lib/_internal/pub/lib/src/barback/dependency_computer.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/barback/dependency_computer.dart
@@ -44,8 +44,8 @@ class DependencyComputer {
 
   DependencyComputer(this._graph) {
     for (var package in ordered(_graph.packages.keys)) {
-      if (_graph.transitiveDependencies(package).every((dependency) =>
-            dependency.pubspec.transformers.isEmpty)) {
+      if (_graph.transitiveDependencies(
+          package).every((dependency) => dependency.pubspec.transformers.isEmpty)) {
         _untransformedPackages.add(package);
       }
     }
@@ -64,8 +64,8 @@ class DependencyComputer {
   /// 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`.
-  Map<TransformerId, Set<TransformerId>> transformersNeededByTransformers(
-      [Iterable<TransformerId> transformers]) {
+  Map<TransformerId, Set<TransformerId>>
+      transformersNeededByTransformers([Iterable<TransformerId> transformers]) {
     var result = {};
 
     if (transformers == null) {
@@ -96,8 +96,8 @@ class DependencyComputer {
   Set<TransformerId> transformersNeededByLibrary(AssetId id) {
     var library = _graph.packages[id.package].path(p.fromUri(id.path));
     _loadPackageComputer(id.package);
-    return _packageComputers[id.package].transformersNeededByLibrary(library)
-        .where((id) => !id.isBuiltInTransformer).toSet();
+    return _packageComputers[id.package].transformersNeededByLibrary(
+        library).where((id) => !id.isBuiltInTransformer).toSet();
   }
 
   /// Returns the set of all transformers that need to be loaded before [id] is
@@ -119,8 +119,8 @@ class DependencyComputer {
     var package = _graph.packages[packageName];
     if (package == null) {
       // TODO(nweiz): include source range information here.
-      fail('A transformer imported unknown package "$packageName" (in '
-          '"$packageUri").');
+      fail(
+          'A transformer imported unknown package "$packageName" (in ' '"$packageUri").');
     }
 
     var library = package.path('lib', p.joinAll(components.skip(1)));
@@ -168,7 +168,8 @@ class DependencyComputer {
       }
 
       var dependencies = packageName == _graph.entrypoint.root.name ?
-          package.immediateDependencies : package.dependencies;
+          package.immediateDependencies :
+          package.dependencies;
       for (var dep in dependencies) {
         try {
           traversePackage(dep.name);
@@ -239,7 +240,7 @@ class _PackageDependencyComputer {
   final _transitiveExternalDirectives = new Map<String, Set<Uri>>();
 
   _PackageDependencyComputer(DependencyComputer dependencyComputer,
-          String packageName)
+      String packageName)
       : _dependencyComputer = dependencyComputer,
         _package = dependencyComputer._graph.packages[packageName] {
     // If [_package] uses its own transformers, there will be fewer transformers
@@ -311,14 +312,15 @@ class _PackageDependencyComputer {
       if (externalDirectives == null) {
         var rootName = _dependencyComputer._graph.entrypoint.root.name;
         var dependencies = _package.name == rootName ?
-            _package.immediateDependencies : _package.dependencies;
+            _package.immediateDependencies :
+            _package.dependencies;
 
         // If anything transitively imported/exported by [library] within this
         // package is modified by a transformer, we don't know what it will
         // load, so we take the conservative approach and say it depends on
         // everything.
-        return _applicableTransformers.map((config) => config.id).toSet().union(
-            unionAll(dependencies.map((dep) {
+        return _applicableTransformers.map(
+            (config) => config.id).toSet().union(unionAll(dependencies.map((dep) {
           try {
             return _dependencyComputer._transformersNeededByPackage(dep.name);
           } on CycleException catch (error) {
@@ -401,8 +403,8 @@ class _PackageDependencyComputer {
   Set<Uri> _getDirectives(String library) {
     var libraryUri = p.toUri(p.normalize(library));
     var relative = p.toUri(_package.relative(library)).path;
-    if (_applicableTransformers.any((config) =>
-            config.canTransform(relative))) {
+    if (_applicableTransformers.any(
+        (config) => config.canTransform(relative))) {
       _directives[libraryUri] = null;
       return null;
     }
@@ -419,10 +421,9 @@ class _PackageDependencyComputer {
       return null;
     }
 
-    _directives[libraryUri] =
-        parseImportsAndExports(readTextFile(library), name: library)
-        .map((directive) => Uri.parse(directive.uri.stringValue))
-        .toSet();
+    _directives[libraryUri] = parseImportsAndExports(
+        readTextFile(library),
+        name: library).map((directive) => Uri.parse(directive.uri.stringValue)).toSet();
     return _directives[libraryUri];
   }
 }