Fix couple problems with in-body incremental resolution.

pkg/analyzer/lib/src/task/dart.dart

Index: pkg/analyzer/lib/src/task/dart.dart
diff --git a/pkg/analyzer/lib/src/task/dart.dart b/pkg/analyzer/lib/src/task/dart.dart
index da8fcec03cc32cd827dbe223a38b59a3828a0837..51b0aaa0af9c397e8e3cb2e2b6a1ea8077ad463d 100644
--- a/pkg/analyzer/lib/src/task/dart.dart
+++ b/pkg/analyzer/lib/src/task/dart.dart
@@ -975,7 +975,7 @@ final ListResultDescriptor<AnalysisError> STATIC_VARIABLE_RESOLUTION_ERRORS =
 final ListResultDescriptor<AnalysisError>
     STATIC_VARIABLE_RESOLUTION_ERRORS_IN_UNIT =
     new ListResultDescriptor<AnalysisError>(
-        'STATIC_VARIABLE_RESOLUTION_ERRORS_IN_UNIT', null);
+        'STATIC_VARIABLE_RESOLUTION_ERRORS_IN_UNIT', AnalysisError.NO_ERRORS);
 
 /**
  * The additional strong mode errors produced while verifying a
@@ -2656,6 +2656,11 @@ class DartDelta extends Delta {
     currentVisitUnits.clear();
   }
 
+  @override
+  bool gatherRequired() {
+    return true;
+  }
+
   bool hasAffectedHintsVerifyErrors(
       ReferencedNames references, Source refLibrary) {
     for (String superName in references.superToSubs.keys) {