Issue 6711. Fix for NPE in resolver.

compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java

Index: compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
diff --git a/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java b/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
index 49694ff9d1629c016479d627c9ab3d0cdf93f045..1ca3593b0e7cf4e0710d47a3d511ee05466988a6 100644
--- a/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
+++ b/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
@@ -1569,12 +1569,8 @@ public class TypeAnalyzer implements DartCompilationPhase {
 
     private void checkIllegalPrivateAccess(DartNode diagnosticNode, Element element, String name) {
       if (DartIdentifier.isPrivateName(name)) {
-        if (element != null) {
-          Element enclosingLibrary = Elements.getLibraryElement(currentMethod);
-          Element identifierEnclosingLibrary = Elements.getLibraryElement(element);
-          if (!enclosingLibrary.equals(identifierEnclosingLibrary)) {
-            onError(diagnosticNode, TypeErrorCode.ILLEGAL_ACCESS_TO_PRIVATE, name);
-          }
+        if (!Elements.areSameLibrary(currentMethod, element)) {
+          onError(diagnosticNode, TypeErrorCode.ILLEGAL_ACCESS_TO_PRIVATE, name);
         }
       }
     }