Step back and remove more getNode() invocations

compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java

Index: compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java
diff --git a/compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java b/compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java
index 47d3a412a849c85984f8ccb5bfee19164685be9c..c0bee341d8af8448247837556e88460b50ada269 100644
--- a/compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java
+++ b/compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java
@@ -44,12 +44,12 @@ public class TopLevelElementBuilder {
     }
   }
 
-  public void exec(DartUnit unit, DartCompilerContext context) {
-    unit.accept(new Builder());
+  public void exec(LibraryUnit library, DartUnit unit, DartCompilerContext context) {
+    unit.accept(new Builder(library.getElement()));
   }
 
-  public void exec(DartClass cls, DartCompilerContext context) {
-    cls.accept(new Builder());
+  public void exec(LibraryUnit library, DartClass cls, DartCompilerContext context) {
+    cls.accept(new Builder(library.getElement()));
   }
 
   /**
@@ -142,10 +142,6 @@ public class TopLevelElementBuilder {
 
     private LibraryElement library;
 
-    public Builder() {
-      this(null);
-    }
-
     public Builder(LibraryElement library) {
       this.library = library;
     }