Add some additional annotations for tracking pub performance.

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

Index: sdk/lib/_internal/pub_generated/lib/src/barback/asset_environment.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/barback/asset_environment.dart b/sdk/lib/_internal/pub_generated/lib/src/barback/asset_environment.dart
index 0852db7109a075bb3914b3d283114dba85ffc381..5c69d94bcee63b44ed90f899433c3655f6242ad2 100644
--- a/sdk/lib/_internal/pub_generated/lib/src/barback/asset_environment.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/barback/asset_environment.dart
@@ -29,16 +29,41 @@ class AssetEnvironment {
     if (watcherType == null) watcherType = WatcherType.NONE;
     if (hostname == null) hostname = "localhost";
     if (basePort == null) basePort = 0;
-    return entrypoint.loadPackageGraph().then((graph) {
-      log.fine("Loaded package graph.");
-      graph = _adjustPackageGraph(graph, mode, packages);
-      var barback = new Barback(new PubPackageProvider(graph));
-      barback.log.listen(_log);
-      var environment =
-          new AssetEnvironment._(graph, barback, mode, watcherType, hostname, basePort);
-      return environment._load(
-          entrypoints: entrypoints,
-          useDart2JS: useDart2JS).then((_) => environment);
+    return log.progress("Loading asset environment", () {
+      final completer0 = new Completer();
+      scheduleMicrotask(() {
+        try {
+          entrypoint.loadPackageGraph().then((x0) {
+            try {
+              var graph = x0;
+              graph = _adjustPackageGraph(graph, mode, packages);
+              var barback = new Barback(new PubPackageProvider(graph));
+              barback.log.listen(_log);
+              var environment =
+                  new AssetEnvironment._(graph, barback, mode, watcherType, hostname, basePort);
+              environment._load(
+                  entrypoints: entrypoints,
+                  useDart2JS: useDart2JS).then((x1) {
+                try {
+                  x1;
+                  completer0.complete(environment);
+                } catch (e1) {
+                  completer0.completeError(e1);
+                }
+              }, onError: (e2) {
+                completer0.completeError(e2);
+              });
+            } catch (e0) {
+              completer0.completeError(e0);
+            }
+          }, onError: (e3) {
+            completer0.completeError(e3);
+          });
+        } catch (e4) {
+          completer0.completeError(e4);
+        }
+      });
+      return completer0.future;
     });
   }
   static PackageGraph _adjustPackageGraph(PackageGraph graph, BarbackMode mode,
@@ -325,7 +350,10 @@ class AssetEnvironment {
               ((transformers) =>
                   transformers.any((config) => config.id.package == '\$dart2js')));
           join0() {
-            BarbackServer.bind(this, _hostname, 0).then((x0) {
+            log.progress(
+                "Binding barback server",
+                (() => BarbackServer.bind(this, _hostname, 0)),
+                fine: true).then((x0) {
               try {
                 var transformerServer = x0;
                 var errorStream = barback.errors.map(((error) {