Add TemplateURLFetcherFactory.

Add TemplateURLFetcherFactory for iOS to support downloading and parsing
OSDD(Open Search Description Document) in web pages. This is a prerequisite
for supporting custom search engines.

Bug: 433824
Cq-Include-Trybots: luci.chromium.try:ios-simulator-cronet;luci.chromium.try:ios-simulator-full-configs
Change-Id: I4ec872f6d9e6541009a3353cb63520ede9fc1470
Reviewed-on: https://chromium-review.googlesource.com/c/1288531Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: Yi Su <mrsuyi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600725}

ios/chrome/browser/search_engines/BUILD.gn

@@ -22,6 +22,8 @@ source_set("search_engines") {
     "search_engine_observer_bridge.mm",
     "search_engines_util.cc",
     "search_engines_util.h",
+    "template_url_fetcher_factory.cc",
+    "template_url_fetcher_factory.h",
     "template_url_service_client_impl.cc",
     "template_url_service_client_impl.h",
     "template_url_service_factory.cc",

ios/chrome/browser/search_engines/template_url_fetcher_factory.cc

+// Copyright 2018 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 "ios/chrome/browser/search_engines/template_url_fetcher_factory.h"
+
+#include "base/memory/singleton.h"
+#include "components/keyed_service/ios/browser_state_dependency_manager.h"
+#include "components/search_engines/template_url_fetcher.h"
+#include "ios/chrome/browser/browser_state/browser_state_otr_helper.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/search_engines/template_url_service_factory.h"
+
+namespace ios {
+
+// static
+TemplateURLFetcher* TemplateURLFetcherFactory::GetForBrowserState(
+    ios::ChromeBrowserState* browser_state) {
+  return static_cast<TemplateURLFetcher*>(
+      GetInstance()->GetServiceForBrowserState(browser_state, true));
+}
+
+// static
+TemplateURLFetcherFactory* TemplateURLFetcherFactory::GetInstance() {
+  return base::Singleton<TemplateURLFetcherFactory>::get();
+}
+
+TemplateURLFetcherFactory::TemplateURLFetcherFactory()
+    : BrowserStateKeyedServiceFactory(
+          "TemplateURLFetcher",
+          BrowserStateDependencyManager::GetInstance()) {
+  DependsOn(TemplateURLServiceFactory::GetInstance());
+}
+
+TemplateURLFetcherFactory::~TemplateURLFetcherFactory() {}
+
+std::unique_ptr<KeyedService>
+TemplateURLFetcherFactory::BuildServiceInstanceFor(
+    web::BrowserState* context) const {
+  return std::make_unique<TemplateURLFetcher>(
+      TemplateURLServiceFactory::GetForBrowserState(
+          static_cast<ios::ChromeBrowserState*>(context)));
+}
+
+web::BrowserState* TemplateURLFetcherFactory::GetBrowserStateToUse(
+    web::BrowserState* context) const {
+  return GetBrowserStateRedirectedInIncognito(context);
+}
+
+}  // namespace ios

ios/chrome/browser/search_engines/template_url_fetcher_factory.h

+// Copyright 2018 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.
+
+#ifndef IOS_CHROME_BROWSER_SEARCH_ENGINES_TEMPLATE_URL_FETCHER_FACTORY_H_
+#define IOS_CHROME_BROWSER_SEARCH_ENGINES_TEMPLATE_URL_FETCHER_FACTORY_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "components/keyed_service/ios/browser_state_keyed_service_factory.h"
+
+namespace base {
+template <typename T>
+struct DefaultSingletonTraits;
+}  // namespace base
+
+class TemplateURLFetcher;
+
+namespace ios {
+
+class ChromeBrowserState;
+
+// Singleton that owns all TemplateURLFetchers and associates them with
+// ios::ChromeBrowserState.
+class TemplateURLFetcherFactory : public BrowserStateKeyedServiceFactory {
+ public:
+  static TemplateURLFetcher* GetForBrowserState(
+      ios::ChromeBrowserState* browser_state);
+
+  static TemplateURLFetcherFactory* GetInstance();
+
+ private:
+  friend struct base::DefaultSingletonTraits<TemplateURLFetcherFactory>;
+
+  TemplateURLFetcherFactory();
+  ~TemplateURLFetcherFactory() override;
+
+  std::unique_ptr<KeyedService> BuildServiceInstanceFor(
+      web::BrowserState* context) const override;
+  web::BrowserState* GetBrowserStateToUse(
+      web::BrowserState* context) const override;
+
+  DISALLOW_COPY_AND_ASSIGN(TemplateURLFetcherFactory);
+};
+
+}  // namespace ios
+
+#endif  // IOS_CHROME_BROWSER_SEARCH_ENGINES_TEMPLATE_URL_FETCHER_FACTORY_H_