Update native keyword checking to accommodate frog

compiler/java/com/google/dart/compiler/parser/DartParser.java

Index: compiler/java/com/google/dart/compiler/parser/DartParser.java
===================================================================
--- compiler/java/com/google/dart/compiler/parser/DartParser.java	(revision 4968)
+++ compiler/java/com/google/dart/compiler/parser/DartParser.java	(working copy)
@@ -617,7 +617,8 @@
     DartStringLiteral nativeName = null;
     if (optionalPseudoKeyword(NATIVE_KEYWORD)) {
       if (superType != null) {
-        reportError(position(), ParserErrorCode.NATIVE_MUST_NOT_EXTEND);
+        // dom_frog.dart has this situation
+        //reportError(position(), ParserErrorCode.NATIVE_MUST_NOT_EXTEND);
       }
       if (isParsingInterface) {
         reportError(position(), ParserErrorCode.NATIVE_ONLY_CLASS);
@@ -1212,15 +1213,16 @@
     if (!corelibParse) {
       reportError(position(), ParserErrorCode.NATIVE_ONLY_CORE_LIB);
     }
-    if (optional(Token.SEMICOLON)) {
-      return done(new DartNativeBlock());
-    } else if (match(Token.LBRACE) || match(Token.ARROW)) {
-      if (!modifiers.isStatic()) {
-        reportError(position(), ParserErrorCode.EXPORTED_FUNCTIONS_MUST_BE_STATIC);
-      }
+    if (match(Token.STRING)) {
+      parseString();
+    }
+    if (match(Token.LBRACE) || match(Token.ARROW)) {
+      // dom_frog.dart has non-static native methods with string and block
+      //if (!modifiers.isStatic()) {
+      //  reportError(position(), ParserErrorCode.EXPORTED_FUNCTIONS_MUST_BE_STATIC);
+      //}
       return done(parseFunctionStatementBody(true));
     } else {
-      parseString();
       expect(Token.SEMICOLON);
       return done(new DartNativeBlock());
     }