Revert last 4 commits by lrn@

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

Index: pkg/compiler/lib/src/elements/modelx.dart
diff --git a/pkg/compiler/lib/src/elements/modelx.dart b/pkg/compiler/lib/src/elements/modelx.dart
index d07cd7eebf693bc8f1eafc24adfb1e6174503b7a..bf589e1cbac3e78485af13acaca9a847c56183ee 100644
--- a/pkg/compiler/lib/src/elements/modelx.dart
+++ b/pkg/compiler/lib/src/elements/modelx.dart
@@ -767,20 +767,6 @@ class CompilationUnitElementX extends ElementX
     }
     partTag = tag;
     LibraryName libraryTag = library.libraryTag;
-
-    Expression libraryReference = tag.name;
-    if (libraryReference is LiteralString) {
-      // Name is a URI. Resolve and compare to library's URI.
-      String content = libraryReference.dartString.slowToString();
-      Uri uri = this.script.readableUri.resolve(content);
-      Uri expectedUri = library.canonicalUri;
-      if (uri != expectedUri) {
-        // Consider finding a relative URI reference for the error message.
-        reporter.reportWarningMessage(tag.name,
-            MessageKind.LIBRARY_URI_MISMATCH, {'libraryUri': expectedUri});
-      }
-      return;
-    }
     String actualName = tag.name.toString();
     if (libraryTag != null) {
       String expectedName = libraryTag.name.toString();