Refactor ChooserBubbleUiViewDelegate

components/chooser_controller.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/chooser_controller
       'target_name': 'chooser_controller',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../content/content.gyp:content_browser',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
         # Note: sources list duplicated in GN build.
         'chooser_controller/chooser_controller.cc',
         'chooser_controller/chooser_controller.h',
       ],
     },
+    {
+      'target_name': 'chooser_controller_test_support',
+      'type': 'static_library',
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../testing/gmock.gyp:gmock',
+        'chooser_controller',
+      ],
+      'include_dirs': [
+        '..',
+      ],
+      'sources': [
+        # Note: sources list duplicated in GN build.
+        'chooser_controller/mock_chooser_controller.cc',
+        'chooser_controller/mock_chooser_controller.h',
+      ],
+    },
   ],
 }