Add common code for extensions event filtering.

chrome/chrome_tests.gypi

 # Copyright (c) 2012 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.
 {
   'variables' : {
     'pyautolib_sources': [
       'app/chrome_command_ids.h',
       'app/chrome_dll_resource.h',
       'common/automation_constants.h',
       'common/pref_names.cc',
@@ skipping 1864 matching lines @@
         'common/extensions/extension_localization_peer_unittest.cc',
         'common/extensions/extension_message_bundle_unittest.cc',
         'common/extensions/extension_permission_set_unittest.cc',
         'common/extensions/extension_resource_unittest.cc',
         'common/extensions/extension_set_unittest.cc',
         'common/extensions/extension_test_util.h',
         'common/extensions/extension_test_util.cc',
         'common/extensions/extension_unittest.cc',
         'common/extensions/extension_unpacker_unittest.cc',
         'common/extensions/feature_unittest.cc',
+        'common/extensions/filtered_event_router_unittest.cc',
         'common/extensions/manifest_tests/extension_manifest_test.cc',
         'common/extensions/manifest_tests/extension_manifests_background_unittest.cc',
         'common/extensions/manifest_tests/extension_manifests_chromepermission_unittest.cc',
         'common/extensions/manifest_tests/extension_manifests_contentscript_unittest.cc',
         'common/extensions/manifest_tests/extension_manifests_default_unittest.cc',
         'common/extensions/manifest_tests/extension_manifests_devtools_unittest.cc',
         'common/extensions/manifest_tests/extension_manifests_excludematches_unittest.cc',
         'common/extensions/manifest_tests/extension_manifests_experimental_unittest.cc',
         'common/extensions/manifest_tests/extension_manifests_filebrowser_unittest.cc',
         'common/extensions/manifest_tests/extension_manifests_homepage_unittest.cc',
@@ skipping 2812 matching lines @@
               # Use outputs of this action as inputs for the main target build.
               # Seems as a misnomer but makes this happy on Linux (scons).
               'process_outputs_as_sources': 1,
             },
           ],  # 'actions'
         },
       ]
     }],  # 'coverage!=0'
   ],  # 'conditions'
 }