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

sdk/lib/_internal/pub_generated/lib/src/command/build.dart

Index: sdk/lib/_internal/pub_generated/lib/src/command/build.dart
diff --git a/sdk/lib/_internal/pub/lib/src/command/build.dart b/sdk/lib/_internal/pub_generated/lib/src/command/build.dart
similarity index 58%
copy from sdk/lib/_internal/pub/lib/src/command/build.dart
copy to sdk/lib/_internal/pub_generated/lib/src/command/build.dart
index 4b76909f9dae02de7ac68cd3b68556611a445909..80060c86f9d68ce43b5ac3cd50fa68bcc9246b00 100644
--- a/sdk/lib/_internal/pub/lib/src/command/build.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/command/build.dart
@@ -35,111 +35,111 @@ class BuildCommand extends BarbackCommand {
   int builtFiles = 0;
 
   BuildCommand() {
-    argParser.addOption("format",
+    argParser.addOption(
+        "format",
         help: "How output should be displayed.",
-        allowed: ["text", "json"], defaultsTo: "text");
+        allowed: ["text", "json"],
+        defaultsTo: "text");
 
-    argParser.addOption("output", abbr: "o",
+    argParser.addOption(
+        "output",
+        abbr: "o",
         help: "Directory to write build outputs to.",
         defaultsTo: "build");
   }
 
-  Future onRunTransformerCommand() async {
-    cleanDir(outputDirectory);
-
-    var errorsJson = [];
-    var logJson = [];
-
-    // Since this server will only be hit by the transformer loader and isn't
-    // user-facing, just use an IPv4 address to avoid a weird bug on the
-    // OS X buildbots.
-    return AssetEnvironment.create(entrypoint, mode, useDart2JS: true)
-        .then((environment) {
-      // Show in-progress errors, but not results. Those get handled
-      // implicitly by getAllAssets().
-      environment.barback.errors.listen((error) {
-        log.error(log.red("Build error:\n$error"));
-
-        if (log.json.enabled) {
-          // Wrap the error in a map in case we end up decorating it with
-          // more properties later.
-          errorsJson.add({
-            "error": error.toString()
+  Future onRunTransformerCommand() {
+    final completer0 = new Completer();
+    scheduleMicrotask(() {
+      try {
+        cleanDir(outputDirectory);
+        var errorsJson = [];
+        var logJson = [];
+        completer0.complete(
+            AssetEnvironment.create(
+                entrypoint,
+                mode,
+                useDart2JS: true).then(((environment) {
+          environment.barback.errors.listen((error) {
+            log.error(log.red("Build error:\n$error"));
+            if (log.json.enabled) {
+              errorsJson.add({
+                "error": error.toString()
+              });
+            }
           });
-        }
-      });
-
-      // If we're using JSON output, the regular server logging is disabled.
-      // Instead, we collect it here to include in the final JSON result.
-      if (log.json.enabled) {
-        environment.barback.log.listen(
-            (entry) => logJson.add(_logEntryToJson(entry)));
-      }
-
-      return log.progress("Building ${entrypoint.root.name}", () {
-        // Register all of the build directories.
-        // TODO(rnystrom): We don't actually need to bind servers for these, we
-        // just need to add them to barback's sources. Add support to
-        // BuildEnvironment for going the latter without the former.
-        return Future.wait(sourceDirectories.map(
-            (dir) => environment.serveDirectory(dir))).then((_) {
-
-          return environment.barback.getAllAssets();
-        });
-      }).then((assets) {
-        // Find all of the JS entrypoints we built.
-        var dart2JSEntrypoints = assets
-            .where((asset) => asset.id.path.endsWith(".dart.js"))
-            .map((asset) => asset.id);
-
-        return Future.wait(assets.map(_writeAsset)).then((_) {
-          builtFiles += _copyBrowserJsFiles(dart2JSEntrypoints);
-          log.message('Built $builtFiles ${pluralize('file', builtFiles)} '
-              'to "$outputDirectory".');
-
+          if (log.json.enabled) {
+            environment.barback.log.listen(
+                (entry) => logJson.add(_logEntryToJson(entry)));
+          }
+          return log.progress("Building ${entrypoint.root.name}", () {
+            return Future.wait(
+                sourceDirectories.map((dir) => environment.serveDirectory(dir))).then((_) {
+              return environment.barback.getAllAssets();
+            });
+          }).then((assets) {
+            var dart2JSEntrypoints = assets.where(
+                (asset) => asset.id.path.endsWith(".dart.js")).map((asset) => asset.id);
+            return Future.wait(assets.map(_writeAsset)).then((_) {
+              builtFiles += _copyBrowserJsFiles(dart2JSEntrypoints);
+              log.message(
+                  'Built $builtFiles ${pluralize('file', builtFiles)} ' 'to "$outputDirectory".');
+              log.json.message({
+                "buildResult": "success",
+                "outputDirectory": outputDirectory,
+                "numFiles": builtFiles,
+                "log": logJson
+              });
+            });
+          });
+        })).catchError(((error) {
+          if (error is! BarbackException) throw error;
+          log.error(log.red("Build failed."));
           log.json.message({
-            "buildResult": "success",
-            "outputDirectory": outputDirectory,
-            "numFiles": builtFiles,
+            "buildResult": "failure",
+            "errors": errorsJson,
             "log": logJson
           });
-        });
-      });
-    }).catchError((error) {
-      // If [getAllAssets()] throws a BarbackException, the error has already
-      // been reported.
-      if (error is! BarbackException) throw error;
-
-      log.error(log.red("Build failed."));
-      log.json.message({
-        "buildResult": "failure",
-        "errors": errorsJson,
-        "log": logJson
-      });
-
-      return flushThenExit(exit_codes.DATA);
+          return flushThenExit(exit_codes.DATA);
+        })));
+      } catch (e, s) {
+        completer0.completeError(e, s);
+      }
     });
+    return completer0.future;
   }
 
   /// Writes [asset] to the appropriate build directory.
   ///
   /// If [asset] is in the special "packages" directory, writes it to every
   /// build directory.
-  Future _writeAsset(Asset asset) async {
-    // In release mode, strip out .dart files since all relevant ones have been
-    // compiled to JavaScript already.
-    if (mode == BarbackMode.RELEASE && asset.id.extension == ".dart") return;
-
-    var destPath = _idToPath(asset.id);
-
-    // If the asset is from a public directory, copy it into all of the
-    // top-level build directories.
-    if (path.isWithin("packages", destPath)) {
-      return Future.wait(sourceDirectories.map((buildDir) =>
-          _writeOutputFile(asset, path.join(buildDir, destPath))));
-    }
-
-    return _writeOutputFile(asset, destPath);
+  Future _writeAsset(Asset asset) {
+    final completer0 = new Completer();
+    scheduleMicrotask(() {
+      try {
+        join0() {
+          var destPath = _idToPath(asset.id);
+          join1() {
+            completer0.complete(_writeOutputFile(asset, destPath));
+          }
+          if (path.isWithin("packages", destPath)) {
+            completer0.complete(Future.wait(sourceDirectories.map(((buildDir) {
+              return _writeOutputFile(asset, path.join(buildDir, destPath));
+            }))));
+          } else {
+            join1();
+          }
+        }
+        if (mode == BarbackMode.RELEASE && asset.id.extension == ".dart") {
+          completer0.complete(null);
+        } else {
+          join0();
+        }
+      } catch (e, s) {
+        completer0.completeError(e, s);
+      }
+    });
+    return completer0.future;
   }
 
   /// Converts [id] to a relative path in the output directory for that asset.
@@ -198,14 +198,16 @@ class BuildCommand extends BarbackCommand {
     }
 
     // Get all of the subdirectories that contain Dart entrypoints.
-    var entrypointDirs = entrypoints
-        // Convert the asset path to a native-separated one and get the
-        // directory containing the entrypoint.
-        .map((id) => path.dirname(path.fromUri(id.path)))
-        // Don't copy files to the top levels of the build directories since
-        // the normal lib asset copying will take care of that.
-        .where((dir) => path.split(dir).length > 1)
-        .toSet();
+    var entrypointDirs =
+        entrypoints// Convert the asset path to a native-separated one and get the
+    // directory containing the entrypoint.
+    .map(
+        (id) =>
+            path.dirname(
+                path.fromUri(
+                    id.path)))// Don't copy files to the top levels of the build directories since
+    // the normal lib asset copying will take care of that.
+    .where((dir) => path.split(dir).length > 1).toSet();
 
     for (var dir in entrypointDirs) {
       // TODO(nweiz): we should put browser JS files next to any HTML file
@@ -223,7 +225,11 @@ class BuildCommand extends BarbackCommand {
   /// under `packages/browser/`.
   void _addBrowserJs(String directory, String name) {
     var jsPath = entrypoint.root.path(
-        outputDirectory, directory, 'packages', 'browser', '$name.js');
+        outputDirectory,
+        directory,
+        'packages',
+        'browser',
+        '$name.js');
     ensureDir(path.dirname(jsPath));
 
     // TODO(rnystrom): This won't work if we get rid of symlinks and the top