Remove navigation_service_unittests, along with the service itself.

testing/buildbot/gn_isolate_map.pyl

 ## 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.
 
 # This is a .pyl, or "Python Literal", file. You can treat it just like a
 # .json file, with the following exceptions:
 # * all keys must be quoted (use single quotes, please);
 # * comments are allowed, using '#' syntax; and
 # * trailing commas are allowed.
 
@@ skipping 762 matching lines @@
   "nacl_helper_nonsfi_unittests": {
     "label": "//components/nacl/loader:nacl_helper_nonsfi_unittests",
     "type": "raw",
     "args": [],
   },
   "nacl_loader_unittests": {
     "label": "//components/nacl/loader:nacl_loader_unittests",
     "type": "raw",
     "args": [],
   },
-  "navigation_unittests": {
-    "label": "//services/navigation:navigation_unittests",
-    "type": "windowed_test_launcher",
-  },
   "net_junit_tests": {
     "label": "//net/android:net_junit_tests",
     "type": "junit_test",
   },
   "net_unittests": {
     "label": "//net:net_unittests",
     "type": "console_test_launcher",
   },
   "next_version_mini_installer": {
     "label": "//chrome/installer/mini_installer:next_version_mini_installer",
@@ skipping 334 matching lines @@
   },
   "wm_unittests": {
     "label": "//ui/wm:wm_unittests",
     "type": "windowed_test_launcher",
   },
   "wtf_unittests": {
     "label": "//third_party/WebKit/Source/platform/wtf:wtf_unittests",
     "type": "console_test_launcher",
   },
 }