Adding a new component, Previews.

components/previews.gypi

 # 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: //components/base32
-      'target_name': 'base32',
+      # GN version: //components/previews
+      'target_name': 'previews',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'dependencies': [
         '../base/base.gyp:base',
+        'variations',
       ],
       'sources': [
-        'base32/base32.h',
-        'base32/base32.cc',
-      ],
-    }
+        'previews/previews_experiments.cc',
+        'previews/previews_experiments.h',
+      ]
+    },
   ],
 }