Add StaleWhileRevalidateExperiment histograms.

chrome/chrome_browser_ui.gypi

 # Copyright 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': {
     # There are two sections of sources:
     # * "Platform"-based sources (OS, toolkit, etc.)
     # * Feature/directory-based sources (e.g., history, printing)
 
@@ skipping 2847 matching lines @@
             '../components/components.gyp:app_modal',
             '../components/components.gyp:autofill_content_risk_proto',
             '../components/components.gyp:crash_core_browser',
             '../components/components.gyp:flags_ui',
             '../components/components.gyp:net_log',
             '../components/components.gyp:page_load_metrics_browser',
             '../components/components.gyp:translate_content_common',
             '../content/app/resources/content_resources.gyp:content_resources',
             '../media/media.gyp:media',
             '../net/net.gyp:net_with_v8',
+            '../net/net.gyp:stale_while_revalidate_experiment_domains',
             '../storage/storage_browser.gyp:storage',
             '../storage/storage_common.gyp:storage_common',
             '../third_party/leveldatabase/leveldatabase.gyp:leveldatabase',
             '../third_party/mojo/mojo_edk.gyp:mojo_system_impl',
             '../third_party/re2/re2.gyp:re2',
             '../ui/base/ime/ui_base_ime.gyp:ui_base_ime',
             '../ui/compositor/compositor.gyp:compositor',
             '../ui/native_theme/native_theme.gyp:native_theme',
             '../ui/surface/surface.gyp:surface',
             '../ui/web_dialogs/web_dialogs.gyp:web_dialogs',
@@ skipping 390 matching lines @@
           ],
           'sources': [
             '<@(chrome_browser_ui_non_mobile_sources)',
             '<@(chrome_browser_ui_omnibox_non_mobile_sources)',
           ],
         }],
       ],
     },
   ],
 }