Delete unused chrome://fallback-icon/ handling

chrome/browser/favicon/chrome_fallback_icon_client_factory.cc

-// Copyright 2015 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.
-
-#include "chrome/browser/favicon/chrome_fallback_icon_client_factory.h"
-
-#include "base/memory/singleton.h"
-#include "chrome/browser/favicon/chrome_fallback_icon_client.h"
-#include "chrome/browser/profiles/incognito_helpers.h"
-#include "components/keyed_service/content/browser_context_dependency_manager.h"
-#include "content/public/browser/browser_context.h"
-
-ChromeFallbackIconClientFactory::ChromeFallbackIconClientFactory()
-    : BrowserContextKeyedServiceFactory(
-        "ChromeFallbackIconClient",
-        BrowserContextDependencyManager::GetInstance()) {
-}
-
-ChromeFallbackIconClientFactory::~ChromeFallbackIconClientFactory() {
-}
-
-// static
-favicon::FallbackIconClient*
-ChromeFallbackIconClientFactory::GetForBrowserContext(
-    content::BrowserContext* context) {
-  return static_cast<favicon::FallbackIconClient*>(
-      GetInstance()->GetServiceForBrowserContext(context, true));
-}
-
-// static
-ChromeFallbackIconClientFactory*
-ChromeFallbackIconClientFactory::GetInstance() {
-  return base::Singleton<ChromeFallbackIconClientFactory>::get();
-}
-
-KeyedService* ChromeFallbackIconClientFactory::BuildServiceInstanceFor(
-    content::BrowserContext* context) const {
-  return new ChromeFallbackIconClient();
-}