Renaming IndexOutOfRangeException to RangeError.

runtime/lib/string_base.dart

Index: runtime/lib/string_base.dart
diff --git a/runtime/lib/string_base.dart b/runtime/lib/string_base.dart
index 9bc0264668ca62738d6ba57352f6d7e42a90c012..6471f837de29c79e9509e28c6bcc80be68f89fab 100644
--- a/runtime/lib/string_base.dart
+++ b/runtime/lib/string_base.dart
@@ -144,13 +144,13 @@ class _StringBase {
     if (endIndex === null) endIndex = this.length;
 
     if ((startIndex < 0) || (startIndex > this.length)) {
-      throw new IndexOutOfRangeException(startIndex);
+      throw new RangeError(startIndex);
     }
     if ((endIndex < 0) || (endIndex > this.length)) {
-      throw new IndexOutOfRangeException(endIndex);
+      throw new RangeError(endIndex);
     }
     if (startIndex > endIndex) {
-      throw new IndexOutOfRangeException(startIndex);
+      throw new RangeError(startIndex);
     }
     return _substringUnchecked(startIndex, endIndex);
   }
@@ -469,7 +469,7 @@ class _StringMatch implements Match {
 
   String group(int group) {
     if (group != 0) {
-      throw new IndexOutOfRangeException(group);
+      throw new RangeError(group);
     }
     return pattern;
   }