Issue 3340. conflict of a library prefix and a name in the importing library should produce a compi…

compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java

Index: compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
diff --git a/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java b/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
index 9efd3dacc772808896c28a43a95102632fe9459b..b8b50ff85c9b3b38ea86ede210c98e125cc3c5a4 100644
--- a/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
+++ b/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
@@ -92,10 +92,9 @@ public class ResolutionContext implements ResolutionErrorListener {
             && !Elements.isArtificialAssertMethod(existingElement)) {
           SourceInfo nameSourceInfo = element.getNameLocation();
           String existingLocation = Elements.getRelativeElementLocation(element, existingElement);
-          // TODO(scheglov) remove condition once HTML will be fixed to don't have duplicates.
-          // http://code.google.com/p/dart/issues/detail?id=1060
-          if (!Elements.isLibrarySource(element.getSourceInfo().getSource(), "html.dart")
-              && !Elements.isLibrarySource(element.getSourceInfo().getSource(), "dom.dart")) {
+          if (existingElement.getKind() == ElementKind.LIBRARY_PREFIX) {
+            onError(nameSourceInfo, ResolverErrorCode.CANNOT_HIDE_IMPORT_PREFIX, name);
+          } else {
             onError(nameSourceInfo, warningCode, name, existingElement, existingLocation);
           }
         }