Revert "dart2js: add support for configuration-specific imports."

pkg/compiler/lib/src/tree/unparser.dart

Index: pkg/compiler/lib/src/tree/unparser.dart
diff --git a/pkg/compiler/lib/src/tree/unparser.dart b/pkg/compiler/lib/src/tree/unparser.dart
index 807ea0514b9ee1d1b0f32471662f24486ac2ffb2..6f141fdf88eb4fec07ebf6111637976ece88190f 100644
--- a/pkg/compiler/lib/src/tree/unparser.dart
+++ b/pkg/compiler/lib/src/tree/unparser.dart
@@ -782,33 +782,9 @@ class Unparser extends Indentation implements Visitor {
     newline();
   }
 
-  visitConditionalUri(ConditionalUri node) {
-    write(node.ifToken.value);
-    space();
-    write('(');
-    visit(node.key);
-    if (node.value != null) {
-      space();
-      write("==");
-      space();
-      visit(node.value);
-    }
-    write(")");
-    space();
-    visit(node.uri);
-  }
-
-  visitDottedName(DottedName node) {
-    unparseNodeListOfIdentifiers(node.identifiers);
-  }
-
   visitImport(Import node) {
     addToken(node.importKeyword);
     visit(node.uri);
-    if (node.hasConditionalUris) {
-      write(' ');
-      visitNodeList(node.conditionalUris);
-    }
     if (node.isDeferred) {
       write(' deferred');
     }
@@ -827,10 +803,6 @@ class Unparser extends Indentation implements Visitor {
   visitExport(Export node) {
     addToken(node.exportKeyword);
     visit(node.uri);
-    if (node.hasConditionalUris) {
-      write(' ');
-      visitNodeList(node.conditionalUris);
-    }
     if (node.combinators != null) {
       write(' ');
       visit(node.combinators);