Use a real package-root for all of our samples instead of buildDir/packages/

dart/tools/testing/dart/status_file_parser.dart

Index: dart/tools/testing/dart/status_file_parser.dart
diff --git a/dart/tools/testing/dart/status_file_parser.dart b/dart/tools/testing/dart/status_file_parser.dart
index 48397572fa2573167245d8371486aa9393d40702..7d12efbdc114ca825ef9ca1f606aa27e384f6b1f 100644
--- a/dart/tools/testing/dart/status_file_parser.dart
+++ b/dart/tools/testing/dart/status_file_parser.dart
@@ -25,6 +25,7 @@ class Expectation {
   static Expectation STATIC_WARNING = byName('StaticWarning');
   static Expectation MISSING_STATIC_WARNING =
       byName('MissingStaticWarning');
+  static Expectation PUB_GET_ERROR = byName('PubGetError');
 
   // "meta expectations"
   static Expectation OK = byName('Ok');
@@ -67,6 +68,8 @@ class Expectation {
       build("MissingStaticWarning", group: fail);
       build("StaticWarning", group: fail);
 
+      build("PubGetError", group: fail);
+
       build("Skip", isMetaExpectation: true);
       build("SkipByDesign", isMetaExpectation: true);
       build("Ok", isMetaExpectation: true);