Support directories other than "web" in pub build.

sdk/lib/_internal/pub/test/build/includes_assets_from_dependencies_test.dart

Index: sdk/lib/_internal/pub/test/build/includes_assets_from_dependencies_test.dart
diff --git a/sdk/lib/_internal/pub/test/build/includes_assets_from_dependencies_test.dart b/sdk/lib/_internal/pub/test/build/includes_assets_from_dependencies_test.dart
index 1455808d965975d28c96c4d59c22360b4af67a77..a5098b63eff6fe497211a4f7d44d4369ee3ae041 100644
--- a/sdk/lib/_internal/pub/test/build/includes_assets_from_dependencies_test.dart
+++ b/sdk/lib/_internal/pub/test/build/includes_assets_from_dependencies_test.dart
@@ -29,24 +29,39 @@ main() {
       d.appPubspec({
         "foo": {"path": "../foo"}
       }),
+      d.dir("example", [
+        d.file("index.html", "html"),
+      ]),
       d.dir("web", [
         d.file("index.html", "html"),
       ])
     ]).create();
 
-    schedulePub(args: ["build"],
-        output: new RegExp(r"Built 3 files!"),
-        exitCode: 0);
+    schedulePub(args: ["build", "--all"],
+        output: new RegExp(r"Built 6 files!"));
 
     d.dir(appPath, [
       d.dir('build', [
-        d.file("index.html", "html"),
-        d.dir('assets', [
-          d.dir('foo', [
-            d.file('foo.txt', 'foo'),
-            d.dir('sub', [
-              d.file('bar.txt', 'bar'),
-            ]),
+        d.dir('example', [
+          d.file("index.html", "html"),
+          d.dir('assets', [
+            d.dir('foo', [
+              d.file('foo.txt', 'foo'),
+              d.dir('sub', [
+                d.file('bar.txt', 'bar'),
+              ]),
+            ])
+          ])
+        ]),
+        d.dir('web', [
+          d.file("index.html", "html"),
+          d.dir('assets', [
+            d.dir('foo', [
+              d.file('foo.txt', 'foo'),
+              d.dir('sub', [
+                d.file('bar.txt', 'bar'),
+              ]),
+            ])
           ])
         ])
       ])