Move common URIs to common/names.dart

pkg/compiler/lib/src/elements/common.dart

Index: pkg/compiler/lib/src/elements/common.dart
diff --git a/pkg/compiler/lib/src/elements/common.dart b/pkg/compiler/lib/src/elements/common.dart
index e27317584b87fc14830a5f4727b48c11029bb85e..f70e43f330ebbd23593e8013799cc363a87f7ce0 100644
--- a/pkg/compiler/lib/src/elements/common.dart
+++ b/pkg/compiler/lib/src/elements/common.dart
@@ -7,7 +7,8 @@
 library elements.common;
 
 import '../common/names.dart' show
-    Names;
+    Names,
+    Uris;
 import '../compiler.dart' show
     Compiler,
     isPrivateName;
@@ -123,7 +124,7 @@ abstract class ElementCommon implements Element {
 
 abstract class LibraryElementCommon implements LibraryElement {
   @override
-  bool get isDartCore => canonicalUri == Compiler.DART_CORE;
+  bool get isDartCore => canonicalUri == Uris.dart_core;
 
   @override
   bool get isPlatformLibrary => canonicalUri.scheme == 'dart';