Roll forward commits r33138, r33135, and r33134.

pkg/barback/test/package_graph/errors_test.dart

Index: pkg/barback/test/package_graph/errors_test.dart
diff --git a/pkg/barback/test/package_graph/errors_test.dart b/pkg/barback/test/package_graph/errors_test.dart
index 417e82449d3120dd76dc68a11fcbd83ccc40912b..9b674094348b8957c799493bc552ac423f3be9e2 100644
--- a/pkg/barback/test/package_graph/errors_test.dart
+++ b/pkg/barback/test/package_graph/errors_test.dart
@@ -114,15 +114,6 @@ main() {
     buildShouldFail([isTransformerException(equals(BadTransformer.ERROR))]);
   });
 
-  test("doesn't yield a source if a transform fails on it", () {
-    initGraph(["app|foo.txt"], {"app": [
-      [new BadTransformer(["app|foo.txt"])]
-    ]});
-
-    updateSources(["app|foo.txt"]);
-    expectNoAsset("app|foo.txt");
-  });
-
   test("catches errors even if nothing is waiting for process results", () {
     initGraph(["app|foo.txt"], {"app": [[new BadTransformer([])]]});