Initial support for hide and show in import directives

compiler/java/com/google/dart/compiler/ast/DartImportDirective.java

Index: compiler/java/com/google/dart/compiler/ast/DartImportDirective.java
===================================================================
--- compiler/java/com/google/dart/compiler/ast/DartImportDirective.java	(revision 9085)
+++ compiler/java/com/google/dart/compiler/ast/DartImportDirective.java	(working copy)
@@ -4,16 +4,24 @@
 
 package com.google.dart.compiler.ast;
 
+import java.util.List;
+
 /**
  * Implements the #import directive.
  */
 public class DartImportDirective extends DartDirective {
   private DartStringLiteral libraryUri;
 
+  private DartBooleanLiteral exported;
+
+  private NodeList<ImportCombinator> combinators = new NodeList<ImportCombinator>(this);
+
   private DartStringLiteral prefix;
 
-  public DartImportDirective(DartStringLiteral libraryUri, DartStringLiteral prefix) {
+  public DartImportDirective(DartStringLiteral libraryUri, DartBooleanLiteral exported, List<ImportCombinator> combinators, DartStringLiteral prefix) {
     this.libraryUri = becomeParentOf(libraryUri);
+    this.exported = becomeParentOf(exported);
+    this.combinators.addAll(combinators);
     this.prefix = becomeParentOf(prefix);
   }
 
@@ -21,6 +29,14 @@
     return libraryUri;
   }
 
+  public DartBooleanLiteral getExported() {
+    return exported;
+  }
+
+  public List<ImportCombinator> getCombinators() {
+    return combinators;
+  }
+
   public DartStringLiteral getPrefix() {
     return prefix;
   }
@@ -28,6 +44,10 @@
   @Override
   public void visitChildren(ASTVisitor<?> visitor) {
     libraryUri.accept(visitor);
+    if (exported != null) {
+      exported.accept(visitor);
+    }
+    combinators.accept(visitor);
     if (prefix != null) {
       prefix.accept(visitor);
     }