[Fallback Icons] Refactor FallbackIconService to be a BrowserContext-level singleton

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 "chrome/browser/profiles/profile.h"

[pkotwicz, 2015/03/27 03:52:09]

Nit: Including profile.h is unnecessary because you don't do anything with the
profile. (You just pass it on to GetServiceForBrowserContext())

[huangs, 2015/03/27 17:33:07]

GetServiceForBrowserContext() call has an implicit upcast from Profile to
content::BrowserContext.

However, digging deeper I realized I can do more refactoring and replace Profile
with BrowserContext.

+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+
+ChromeFallbackIconClientFactory::ChromeFallbackIconClientFactory()
+    : BrowserContextKeyedServiceFactory(
+        "ChromeFallbackIconClient",
+        BrowserContextDependencyManager::GetInstance()) {
+}
+
+ChromeFallbackIconClientFactory::~ChromeFallbackIconClientFactory() {
+}
+
+// static
+FallbackIconClient* ChromeFallbackIconClientFactory::GetForProfile(
+    Profile* profile) {
+  return static_cast<FallbackIconClient*>(
+      GetInstance()->GetServiceForBrowserContext(profile, true));
+}
+
+// static
+ChromeFallbackIconClientFactory*
+ChromeFallbackIconClientFactory::GetInstance() {
+  return Singleton<ChromeFallbackIconClientFactory>::get();
+}
+
+KeyedService* ChromeFallbackIconClientFactory::BuildServiceInstanceFor(
+    content::BrowserContext* context) const {
+  ChromeFallbackIconClient* client = new ChromeFallbackIconClient();
+  return client;

[pkotwicz, 2015/03/27 03:52:09]

Nit: "return new ChromeFallbackIconClient();"

[huangs, 2015/03/27 17:33:07]

Done.

+}
+
+content::BrowserContext*
+ChromeFallbackIconClientFactory::GetBrowserContextToUse(
+    content::BrowserContext* context) const {
+  return chrome::GetBrowserContextRedirectedInIncognito(context);
+}