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

sdk/lib/_internal/compiler/implementation/apiimpl.dart

Index: sdk/lib/_internal/compiler/implementation/apiimpl.dart
diff --git a/sdk/lib/_internal/compiler/implementation/apiimpl.dart b/sdk/lib/_internal/compiler/implementation/apiimpl.dart
index 69d3cfa36629232ab0103b9f56eb0dbd9f96f0ea..c582bc082ed6da39d177206fc20eea9ead98e5a2 100644
--- a/sdk/lib/_internal/compiler/implementation/apiimpl.dart
+++ b/sdk/lib/_internal/compiler/implementation/apiimpl.dart
@@ -4,7 +4,6 @@
 
 library leg_apiimpl;
 
-import 'dart:uri';
 import 'dart:async';
 
 import '../compiler.dart' as api;
@@ -136,7 +135,7 @@ class Compiler extends leg.Compiler {
 
   elements.LibraryElement scanBuiltinLibrary(String path) {
     Uri uri = libraryRoot.resolve(lookupLibraryPath(path));
-    Uri canonicalUri = new Uri.fromComponents(scheme: "dart", path: path);
+    Uri canonicalUri = new Uri(scheme: "dart", path: path);
     elements.LibraryElement library =
         libraryLoader.loadLibrary(uri, null, canonicalUri);
     return library;