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

pkg/compiler/lib/src/library_loader.dart

Index: pkg/compiler/lib/src/library_loader.dart
diff --git a/pkg/compiler/lib/src/library_loader.dart b/pkg/compiler/lib/src/library_loader.dart
index 6006bc93b4d19971920fd2adcc0ac0f19f98ca01..f0b296b1581b9663c8886a416fb63127667a9264 100644
--- a/pkg/compiler/lib/src/library_loader.dart
+++ b/pkg/compiler/lib/src/library_loader.dart
@@ -384,21 +384,7 @@ class _LibraryLoaderTask extends CompilerTask implements LibraryLoaderTask {
       return reporter.withCurrentElement(library, () {
 
         Uri computeUri(LibraryDependency node) {
-          StringNode uriNode = node.uri;
-          if (node.conditionalUris != null) {
-            for (ConditionalUri conditionalUri in node.conditionalUris) {
-              String key = conditionalUri.key.slowNameString;
-              String value = conditionalUri.value == null
-                  ? "true"
-                  : conditionalUri.value.dartString.slowToString();
-              String actual = compiler.fromEnvironment(key);
-              if (value == actual) {
-                uriNode = conditionalUri.uri;
-                break;
-              }
-            }
-          }
-          String tagUriString = uriNode.dartString.slowToString();
+          String tagUriString = node.uri.dartString.slowToString();
           try {
             return Uri.parse(tagUriString);
           } on FormatException {