Remove GYP files.

third_party/netty4/netty.gyp

Index: third_party/netty4/netty.gyp
diff --git a/third_party/netty4/netty.gyp b/third_party/netty4/netty.gyp
deleted file mode 100644
index 5a9bac12ed0e8b0f30d567a4b6bc037ff6daa9ec..0000000000000000000000000000000000000000
--- a/third_party/netty4/netty.gyp
+++ /dev/null
@@ -1,16 +0,0 @@
-# Copyright (c) 2010 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-{
-  'targets': [
-    { # This target references prebuilt Netty Jar file.
-      'target_name': 'netty_all',
-      'type' : 'none',
-      'variables': {
-        'jar_path': 'src/jar/all-in-one/netty-all-4.1.0.CR1-20160111.120759-50.jar',
-        'exclude_from_apk': 1,
-      },
-      'includes': ['../../build/java_prebuilt.gypi'],
-    },
-  ],
-}