Remove GYP files in breakpad, build, and tools.

build/linux/unbundle/libpng.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': 'libpng',
-      'type': 'none',
-      'dependencies': [
-        '../zlib/zlib.gyp:zlib',
-      ],
-      'direct_dependent_settings': {
-        'cflags': [
-          '<!@(pkg-config --cflags libpng)',
-        ],
-      },
-      'link_settings': {
-        'ldflags': [
-          '<!@(pkg-config --libs-only-L --libs-only-other libpng)',
-        ],
-        'libraries': [
-          '<!@(pkg-config --libs-only-l libpng)',
-        ],
-      },
-      'variables': {
-        'headers_root_path': '.',
-        'header_filenames': [
-          'png.h',
-          'pngconf.h',
-        ],
-      },
-      'includes': [
-        '../../build/shim_headers.gypi',
-      ],
-    },
-  ],
-}