Remove GYP files.

ios/third_party/fishhook/fishhook.gyp

Index: ios/third_party/fishhook/fishhook.gyp
diff --git a/ios/third_party/fishhook/fishhook.gyp b/ios/third_party/fishhook/fishhook.gyp
deleted file mode 100644
index 968eb044f6ac3211bc9f0eeb8893dc9a7160a057..0000000000000000000000000000000000000000
--- a/ios/third_party/fishhook/fishhook.gyp
+++ /dev/null
@@ -1,22 +0,0 @@
-# Copyright 2016 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': [
-    {
-      # GN version: //ios/third_party/fishhook
-      'target_name': 'fishhook',
-      'type': 'static_library',
-      'sources': [
-        'src/fishhook.c',
-        'src/fishhook.h',
-      ],
-      'direct_dependent_settings': {
-        'include_dirs': [
-          'src'
-        ],
-      },
-    },
-  ],
-}