Do not restrict the visibility of webkit_unit_tests to only third_party/WebKit.

Source/web/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//third_party/WebKit/Source/bindings/bindings.gni")
 import("//third_party/WebKit/Source/config.gni")
 import("//third_party/WebKit/Source/core/core.gni")
 import("//third_party/WebKit/Source/modules/modules.gni")
@@ skipping 88 matching lines @@
     include_dirs = [
       "$root_gen_dir/blink",
     ]
   }
 }
 
 # GYP version: WebKit/Source/web/web_tests.gyp:webkit_unit_tests
 if (!is_mac) {
   # TODO(GYP): Can't link Blink binaries yet on mac.
   test("webkit_unit_tests") {
+    visibility = []  # Allow re-assignment of list.
+    visibility = [ "*" ]
+
     deps = [
       ":test_support",
       ":web",
       "//base",
       "//base/test:test_support",
       "//base:i18n",
       "//content/test:test_support",
       "//testing/gmock",
       "//testing/gtest",
       "//third_party/WebKit/Source/wtf:test_support",
@@ skipping 14 matching lines @@
 
       sources += web_gypi.web_unittest_files
       sources += bindings_unittest_files
       sources += core_unittest_files
       sources += modules_unittest_files
       sources += platform_unittest_support_files
       sources += platform_web_unittest_files
     }
   }
 }