Delete unused chrome://fallback-icon/ handling

chrome/browser/ui/BUILD.gn

 # 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.
 
 import("//build/config/chromecast_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 326 matching lines @@
     "webui/cookies_tree_model_util.cc",
     "webui/cookies_tree_model_util.h",
     "webui/crashes_ui.cc",
     "webui/crashes_ui.h",
     "webui/device_log_ui.cc",
     "webui/device_log_ui.h",
     "webui/domain_reliability_internals_ui.cc",
     "webui/domain_reliability_internals_ui.h",
     "webui/engagement/site_engagement_ui.cc",
     "webui/engagement/site_engagement_ui.h",
-    "webui/fallback_icon_source.cc",
-    "webui/fallback_icon_source.h",
     "webui/favicon_source.cc",
     "webui/favicon_source.h",
     "webui/fileicon_source.cc",
     "webui/fileicon_source.h",
     "webui/flags_ui.cc",
     "webui/flags_ui.h",
     "webui/gcm_internals_ui.cc",
     "webui/gcm_internals_ui.h",
     "webui/instant_ui.cc",
     "webui/instant_ui.h",
@@ skipping 3237 matching lines @@
       "test/test_confirm_bubble_model.cc",
       "test/test_confirm_bubble_model.h",
     ]
     deps += [ "//chrome/test:test_support_ui" ]
   }
 
   if (enable_extensions) {
     deps += [ "//extensions/browser" ]
   }
 }