Issue 1606/1108. The 'native' keyword is supposed to only be allowed in core libraries.

compiler/java/com/google/dart/compiler/CommandLineOptions.java

Index: compiler/java/com/google/dart/compiler/CommandLineOptions.java
diff --git a/compiler/java/com/google/dart/compiler/CommandLineOptions.java b/compiler/java/com/google/dart/compiler/CommandLineOptions.java
index 8290021bdf0028a7fbe36f51529cd95fa63a8cb8..c407e40a38f9207f742fa268141d0c365629edad 100644
--- a/compiler/java/com/google/dart/compiler/CommandLineOptions.java
+++ b/compiler/java/com/google/dart/compiler/CommandLineOptions.java
@@ -125,7 +125,7 @@ public class CommandLineOptions {
     private final List<String> sourceFiles = new ArrayList<String>();
 
     /**
-     * Returns whether the option -check-only is provided.
+     * Returns whether the only analysis should be done, without code generation.
      */
     public boolean checkOnly() {
       return !deprecatedGenerateCode;