Remove frog from the repository.

frog/lib/frog_coreimpl_sources.gypi

Index: frog/lib/frog_coreimpl_sources.gypi
diff --git a/frog/lib/frog_coreimpl_sources.gypi b/frog/lib/frog_coreimpl_sources.gypi
deleted file mode 100644
index 6ae543dc22ae23b0594b6adbe8c23c77f05c6bb1..0000000000000000000000000000000000000000
--- a/frog/lib/frog_coreimpl_sources.gypi
+++ /dev/null
@@ -1,18 +0,0 @@
-# Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-# for details. All rights reserved. Use of this source code is governed by a
-# BSD-style license that can be found in the LICENSE file.
-
-{
-  'sources': [
-    'arrays.dart',
-    'corelib.dart',
-    'corelib_impl.dart',
-    'date_implementation.dart',
-    'function_implementation.dart',
-    'math.dart',
-    'num.dart',
-    'string_base.dart',
-    'string_buffer.dart',
-    'string_implementation.dart',
-  ],
-}