Fixes for translator and DDA status files.

editor/util/plugins/com.google.dart.java2dart/resources/java_core.dart

Index: editor/util/plugins/com.google.dart.java2dart/resources/java_core.dart
diff --git a/editor/util/plugins/com.google.dart.java2dart/resources/java_core.dart b/editor/util/plugins/com.google.dart.java2dart/resources/java_core.dart
index c3dd97079a6d9f2623a696d04a79c74005d23ffa..18888f7710d4fd1f4efd27b9b493ac76df9a102c 100644
--- a/editor/util/plugins/com.google.dart.java2dart/resources/java_core.dart
+++ b/editor/util/plugins/com.google.dart.java2dart/resources/java_core.dart
@@ -84,6 +84,9 @@ class JavaArrays {
 class Character {
   static const int MAX_VALUE = 0xffff;
   static const int MAX_CODE_POINT = 0x10ffff;
+  static const int MIN_SUPPLEMENTARY_CODE_POINT = 0x010000;
+  static const int MIN_LOW_SURROGATE  = 0xDC00;
+  static const int MIN_HIGH_SURROGATE = 0xD800;
   static bool isLetter(int c) {
     return c >= 0x41 && c <= 0x5A || c >= 0x61 && c <= 0x7A;
   }
@@ -109,7 +112,16 @@ class Character {
     return -1;
   }
   static String toChars(int codePoint) {
-    throw new UnsupportedOperationException();
+    if (codePoint < 0 || codePoint > MAX_CODE_POINT) {
+      throw new IllegalArgumentException();
+    }
+    if (codePoint < MIN_SUPPLEMENTARY_CODE_POINT) {
+      return new String.fromCharCode(codePoint);
+    }
+    int offset = codePoint - MIN_SUPPLEMENTARY_CODE_POINT;
+    int c0 = ((offset & 0x7FFFFFFF) >> 10) + MIN_HIGH_SURROGATE;
+    int c1 = (offset & 0x3ff) + MIN_LOW_SURROGATE;
+    return new String.fromCharCodes([c0, c1]);
   }
 }