Log messages regarding why app banners aren't displayed to the console

chrome/chrome_browser.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': {
     # All .cc, .h, .m, and .mm files under browser except for:
     # * tests and mocks.
     # * code below browser/chromeos
     # * code below browser/extensions
@@ skipping 198 matching lines @@
       'browser/autofill/validation_rules_storage_factory.cc',
       'browser/autofill/validation_rules_storage_factory.h',
       'browser/banners/app_banner_data_fetcher.cc',
       'browser/banners/app_banner_data_fetcher.h',
       'browser/banners/app_banner_manager.cc',
       'browser/banners/app_banner_manager.h',
       'browser/banners/app_banner_metrics.cc',
       'browser/banners/app_banner_metrics.h',
       'browser/banners/app_banner_settings_helper.cc',
       'browser/banners/app_banner_settings_helper.h',
+      'browser/banners/app_banner_debug_log.cc',
+      'browser/banners/app_banner_debug_log.h',
       'browser/bitmap_fetcher/bitmap_fetcher.cc',
       'browser/bitmap_fetcher/bitmap_fetcher.h',
       'browser/bitmap_fetcher/bitmap_fetcher_delegate.h',
       'browser/bitmap_fetcher/bitmap_fetcher_service.cc',
       'browser/bitmap_fetcher/bitmap_fetcher_service.h',
       'browser/bitmap_fetcher/bitmap_fetcher_service_factory.cc',
       'browser/bitmap_fetcher/bitmap_fetcher_service_factory.h',
       'browser/browser_about_handler.cc',
       'browser/browser_about_handler.h',
       'browser/browser_shutdown.cc',
@@ skipping 3636 matching lines @@
           'variables': {
             'proto_in_dir': 'browser/sync_file_system/drive_backend',
             'proto_out_dir': 'chrome/browser/sync_file_system/drive_backend',
           },
           'includes': [ '../build/protoc.gypi' ]
         },
       ],
     },],
   ],
 }