Create a spellcheck component that will allow any embedder to reuse common functionality.

components/spellcheck.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.
+
+{
+  'conditions': [
+    ['enable_spellcheck==1', {
+      'targets': [
+        {
+          # GN: //components/spellcheck/common:spellcheck_common
+          'target_name': 'spellcheck_common',
+          'type': 'none',
+          'dependencies': [
+            '../base/base.gyp:base',
+            '../ipc/ipc.gyp:ipc',
+          ],
+          'include_dirs': [
+            '..',
+          ],
+          'sources': [
+            "spellcheck/common/spellcheck_bdict_language.h",
+            "spellcheck/common/spellcheck_marker.h",
+            "spellcheck/common/spellcheck_message.h",
+            "spellcheck/common/spellcheck_result.h",
+          ],
+        },
+      ],
+    }],
+  ],
+}