UserManager stack refactoring.

components/user_manager.gypi

Index: components/user_manager.gypi
diff --git a/components/user_manager.gypi b/components/user_manager.gypi
index 03aba1edc6badb30811b94ffb349f3f80e1e9209..2c85d3fa0f56bd33cf9a70496faf67975ac0440c 100644
--- a/components/user_manager.gypi
+++ b/components/user_manager.gypi
@@ -62,5 +62,22 @@
         'sources': [ '<@(user_manager_chromeos_sources)' ],
       }],
     ],
-  }],
+  },
+  {
+    # GN version: //components/user_manager:test_support
+    'target_name': 'user_manager_test_support',
+    'type': 'static_library',
+    'dependencies': [
+      '<(DEPTH)/base/base.gyp:base',
+      '<(DEPTH)/base/base.gyp:test_support_base',
+      '<(DEPTH)/testing/gmock.gyp:gmock',
+      '<(DEPTH)/testing/gtest.gyp:gtest',
+      'user_manager',
+    ],
+    'sources': [
+      'user_manager/fake_user_manager.cc',
+      'user_manager/fake_user_manager.h',
+      ],
+    },
+  ],
 }