Added an experiment for an LRU snapshot cache.

ios/chrome/ios_chrome_tests.gyp

 # 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.
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
       'target_name': 'ios_chrome_unittests',
@@ skipping 40 matching lines @@
         'browser/metrics/ios_chrome_metrics_service_accessor_unittest.cc',
         'browser/metrics/ios_chrome_stability_metrics_provider_unittest.cc',
         'browser/metrics/ios_stability_metrics_provider_unittest.mm',
         'browser/metrics/previous_session_info_unittest.mm',
         'browser/net/cookie_util_unittest.mm',
         'browser/net/image_fetcher_unittest.mm',
         'browser/net/metrics_network_client_unittest.mm',
         'browser/net/retryable_url_fetcher_unittest.mm',
         'browser/signin/chrome_identity_service_observer_bridge_unittest.mm',
         'browser/signin/gaia_auth_fetcher_ios_unittest.mm',
+        'browser/snapshots/lru_cache_unittest.mm',
         'browser/snapshots/snapshot_cache_unittest.mm',
         'browser/snapshots/snapshots_util_unittest.mm',
         'browser/translate/translate_service_ios_unittest.cc',
         'browser/ui/commands/set_up_for_testing_command_unittest.mm',
         'browser/ui/keyboard/UIKeyCommand+ChromeTest.mm',
         'browser/ui/keyboard/hardware_keyboard_watcher_unittest.mm',
         'browser/ui/native_content_controller_unittest.mm',
         'browser/ui/ui_util_unittest.mm',
         'browser/ui/uikit_ui_util_unittest.mm',
         'browser/update_client/ios_chrome_update_query_params_delegate_unittest.cc',
@@ skipping 44 matching lines @@
         'test/block_cleanup_test.mm',
         'test/ios_chrome_unit_test_suite.cc',
         'test/ios_chrome_unit_test_suite.h',
         'test/run_all_unittests.cc',
         'test/testing_application_context.cc',
         'test/testing_application_context.h',
       ],
     },
   ],
 }