Partially componentize chrome/common/crash_keys.

components/crash_keys.gypi

 # Copyright 2015 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/toolbar
-      'target_name': 'toolbar',
+      # GN version: //components/crash_keys
+      'target_name': 'crash_keys',
       'type': 'static_library',
-      'dependencies': [
-        '../base/base.gyp:base',
-        '../url/url.gyp:url_lib',
-      ],
       'include_dirs': [
         '..',
       ],
+      'dependencies': [
+        # List of dependencies is intentionally very minimal. Please avoid
+        # adding extra dependencies without first checking with OWNERS.
+        '../base/base.gyp:base',
+      ],
       'sources': [
-        # Note: sources list duplicated in GN build.
-        'toolbar/toolbar_model.cc',
-        'toolbar/toolbar_model.h',
+        'crash_keys/crash_keys.cc',
+        'crash_keys/crash_keys.h',
       ],
     },
   ],
 }