[iOS] Add iOS factory for RemoteSuggestionsService

Omnibox NTP Zero-Prefix Suggestions use the RemoteSuggestionsService
to actually get their suggestions. The corresponding factory currently
doesn't exist on iOS, so this CL creates it.

Bug: 1048193
Change-Id: I7ad14129a954e96225adc9d6b000087165ce5859
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2035964
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738520}

ios/chrome/browser/autocomplete/BUILD.gn

@@ -12,6 +12,8 @@ source_set("autocomplete") {
     "autocomplete_scheme_classifier_impl.mm",
     "in_memory_url_index_factory.cc",
     "in_memory_url_index_factory.h",
+    "remote_suggestions_service_factory.h",
+    "remote_suggestions_service_factory.mm",
     "shortcuts_backend_factory.h",
     "shortcuts_backend_factory.mm",
   ]

ios/chrome/browser/autocomplete/autocomplete_provider_client_impl.mm

@@ -17,6 +17,7 @@
 #include "ios/chrome/browser/application_context.h"
 #include "ios/chrome/browser/autocomplete/autocomplete_classifier_factory.h"
 #include "ios/chrome/browser/autocomplete/in_memory_url_index_factory.h"
+#include "ios/chrome/browser/autocomplete/remote_suggestions_service_factory.h"
 #include "ios/chrome/browser/autocomplete/shortcuts_backend_factory.h"
 #include "ios/chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
@@ -101,7 +102,8 @@ AutocompleteProviderClientImpl::GetTemplateURLService() const {
 RemoteSuggestionsService*
 AutocompleteProviderClientImpl::GetRemoteSuggestionsService(
     bool create_if_necessary) const {
-  return nullptr;
+  return RemoteSuggestionsServiceFactory::GetForBrowserState(
+      browser_state_, create_if_necessary);
 }
 
 DocumentSuggestionsService*

ios/chrome/browser/autocomplete/remote_suggestions_service_factory.h

+// Copyright 2020 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_AUTOCOMPLETE_REMOTE_SUGGESTIONS_SERVICE_FACTORY_H_
+#define IOS_CHROME_BROWSER_AUTOCOMPLETE_REMOTE_SUGGESTIONS_SERVICE_FACTORY_H_
+
+#include "base/no_destructor.h"
+#include "components/keyed_service/ios/browser_state_keyed_service_factory.h"
+
+class ChromeBrowserState;
+class RemoteSuggestionsService;
+
+// Singleton that owns all RemoteSuggestionsServices and associates them with
+// ChromeBrowserState.
+class RemoteSuggestionsServiceFactory : public BrowserStateKeyedServiceFactory {
+ public:
+  static RemoteSuggestionsService* GetForBrowserState(
+      ChromeBrowserState* browser_state,
+      bool create_if_necessary);
+  static RemoteSuggestionsServiceFactory* GetInstance();
+
+ private:
+  friend class base::NoDestructor<RemoteSuggestionsServiceFactory>;
+
+  RemoteSuggestionsServiceFactory();
+  ~RemoteSuggestionsServiceFactory() override;
+
+  // BrowserStateKeyedServiceFactory implementation.
+  std::unique_ptr<KeyedService> BuildServiceInstanceFor(
+      web::BrowserState* context) const override;
+
+  RemoteSuggestionsServiceFactory(const RemoteSuggestionsServiceFactory&) =
+      delete;
+  RemoteSuggestionsServiceFactory& operator=(
+      const RemoteSuggestionsServiceFactory&) = delete;
+};
+
+#endif  // IOS_CHROME_BROWSER_AUTOCOMPLETE_REMOTE_SUGGESTIONS_SERVICE_FACTORY_H_

ios/chrome/browser/autocomplete/remote_suggestions_service_factory.mm

+// Copyright 2020 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 "ios/chrome/browser/autocomplete/remote_suggestions_service_factory.h"
+
+#include "base/no_destructor.h"
+#include "components/keyed_service/ios/browser_state_dependency_manager.h"
+#include "components/omnibox/browser/remote_suggestions_service.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "services/network/public/cpp/shared_url_loader_factory.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+// static
+RemoteSuggestionsService* RemoteSuggestionsServiceFactory::GetForBrowserState(
+    ChromeBrowserState* browser_state,
+    bool create_if_necessary) {
+  return static_cast<RemoteSuggestionsService*>(
+      GetInstance()->GetServiceForBrowserState(browser_state,
+                                               create_if_necessary));
+}
+
+// static
+RemoteSuggestionsServiceFactory*
+RemoteSuggestionsServiceFactory::GetInstance() {
+  static base::NoDestructor<RemoteSuggestionsServiceFactory> instance;
+  return instance.get();
+}
+
+std::unique_ptr<KeyedService>
+RemoteSuggestionsServiceFactory::BuildServiceInstanceFor(
+    web::BrowserState* context) const {
+  ChromeBrowserState* browser_state =
+      ChromeBrowserState::FromBrowserState(context);
+  return std::make_unique<RemoteSuggestionsService>(
+      browser_state->GetSharedURLLoaderFactory());
+}
+
+RemoteSuggestionsServiceFactory::RemoteSuggestionsServiceFactory()
+    : BrowserStateKeyedServiceFactory(
+          "RemoteSuggestionsService",
+          BrowserStateDependencyManager::GetInstance()) {}
+
+RemoteSuggestionsServiceFactory::~RemoteSuggestionsServiceFactory() {}