Convert the re2 GYP targets to be generated by GN.

content/content_browser.gypi

 # Copyright (c) 2012 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base_static',
     '../crypto/crypto.gyp:crypto',
     '../google_apis/google_apis.gyp:google_apis',
     '../net/net.gyp:net',
+    '../out/gn_gyp/third_party/re2/re2.gyp:re2',
     '../skia/skia.gyp:skia',
     '../sql/sql.gyp:sql',
-    '../third_party/re2/re2.gyp:re2',
     '../third_party/zlib/google/zip.gyp:zip',
     '../third_party/zlib/zlib.gyp:zlib',
     '../ui/accessibility/accessibility.gyp:accessibility',
     '../ui/events/events.gyp:events_base',
     '../ui/gfx/gfx.gyp:gfx',
     '../ui/gfx/gfx.gyp:gfx_geometry',
     '../ui/resources/ui_resources.gyp:ui_resources',
     '../ui/snapshot/snapshot.gyp:snapshot',
     '../ui/ui.gyp:ui',
     'browser/speech/proto/speech_proto.gyp:speech_proto',
@@ skipping 1604 matching lines @@
         '../build/linux/system.gyp:dbus',
         '../dbus/dbus.gyp:dbus',
       ],
     }, {  # OS != "linux" or use_dbus==0
       'sources!': [
         'browser/geolocation/wifi_data_provider_linux.cc',
       ],
     }],
   ],
 }