Issue 5588. Don't report errors when preProcessLibraryDirectives()

compiler/java/com/google/dart/compiler/DartCompilerMainContext.java

Index: compiler/java/com/google/dart/compiler/DartCompilerMainContext.java
diff --git a/compiler/java/com/google/dart/compiler/DartCompilerMainContext.java b/compiler/java/com/google/dart/compiler/DartCompilerMainContext.java
index ac44af98cfd42458efd4e63c23922826413145d9..4643e1cbb4496ba58f66197f0d93682eb29cc4c8 100644
--- a/compiler/java/com/google/dart/compiler/DartCompilerMainContext.java
+++ b/compiler/java/com/google/dart/compiler/DartCompilerMainContext.java
@@ -92,7 +92,7 @@ final class DartCompilerMainContext implements DartCompilerListener, DartCompile
         if (appLibraryUnit == null) {
           try {
             appLibraryUnit = new DartParser(lib, DartParser.read(lib), false,
-                Sets.<String> newHashSet(), listener, null).preProcessLibraryDirectives(lib);
+                Sets.<String> newHashSet(), DartCompilerListener.EMPTY, null).preProcessLibraryDirectives(lib);
           } catch (IOException e) {
             onError(new DartCompilationError(lib, DartCompilerErrorCode.IO, e.getMessage()));
             return null;