Remove use_system_openssl.

Since the BoringSSL switch, this cannot possibly work. (There isn't an
openssl.gyp to swap out anyway.)

BUG=none

Review URL: https://codereview.chromium.org/859073002

Cr-Original-Commit-Position: refs/heads/master@{#312452}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 2b60792760a1291c50594f213a0bc5e71d020e4d

linux/unbundle/openssl.gyp

@@ -1,25 +0,0 @@
-# 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': 'openssl',
-      'type': 'none',
-      'direct_dependent_settings': {
-        'cflags': [
-          '<!@(pkg-config --cflags openssl)',
-        ],
-      },
-      'link_settings': {
-        'ldflags': [
-          '<!@(pkg-config --libs-only-L --libs-only-other openssl)',
-        ],
-        'libraries': [
-          '<!@(pkg-config --libs-only-l openssl)',
-        ],
-      },
-    }
-  ],
-}

linux/unbundle/replace_gyp_files.py

@@ -31,7 +31,6 @@ REPLACEMENTS = {
   'use_system_libxml': 'third_party/libxml/libxml.gyp',
   'use_system_libxnvctrl' : 'third_party/libXNVCtrl/libXNVCtrl.gyp',
   'use_system_libxslt': 'third_party/libxslt/libxslt.gyp',
-  'use_system_openssl': 'third_party/boringssl/boringssl.gyp',
   'use_system_opus': 'third_party/opus/opus.gyp',
   'use_system_protobuf': 'third_party/protobuf/protobuf.gyp',
   'use_system_re2': 'third_party/re2/re2.gyp',