Merge the dart:uri library into dart:core and update the Uri class

tests/compiler/dart2js/resolution_test.dart

Index: tests/compiler/dart2js/resolution_test.dart
diff --git a/tests/compiler/dart2js/resolution_test.dart b/tests/compiler/dart2js/resolution_test.dart
index c1a327f91d5fcfe4a454f3014ab47f52007ad95c..32f59457a5f015ca4fa6efb6ce3e01460383c7ed 100644
--- a/tests/compiler/dart2js/resolution_test.dart
+++ b/tests/compiler/dart2js/resolution_test.dart
@@ -92,7 +92,7 @@ main() {
 """;
 
 void test(String code, void check(Compiler compiler)) {
-  Uri uri = new Uri.fromComponents(scheme: 'source');
+  Uri uri = new Uri(scheme: 'source');
   var compiler = compilerFor(code, uri);
   compiler.runCompiler(uri);
   check(compiler);