Remove all .gyp and .gypi files.

build/linux/unbundle/libwebp.gyp

-# Copyright 2013 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': [
-    {
-      'target_name': 'libwebp',
-      'type': 'none',
-      'direct_dependent_settings': {
-        'defines': [
-          'ENABLE_WEBP',
-        ],
-      },
-      'link_settings': {
-        'libraries': [
-          # Check for presence of webpdemux library, use it if present.
-          '<!(python <(DEPTH)/tools/compile_test/compile_test.py '
-          '--code "int main() { return 0; }" '
-          '--run-linker '
-          '--on-success "-lwebp -lwebpdemux" '
-          '--on-failure "-lwebp" '
-          '-- -lwebpdemux)',
-        ],
-      },
-    }
-  ],
-}