[ios] Creates DiscoverFeedService

- Creates DiscoverFeedService, a BrowserState KeyedService
- Creates DiscoverFeedServiceFactory to create and own
DiscoverFeedServices
- Initializes DiscoverFeedService in main controller.
- Updates DiscoverFeedProvider interface with methods to start the Feed
and update when the Identity changes.

Bug: 1085419
Change-Id: Ie39653f6263915f9ef69b68d5c1e2182d15c7ab1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2344503Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798272}

ios/chrome/browser/browser_state/BUILD.gn

@@ -96,6 +96,7 @@ source_set("browser_state_impl") {
     "//ios/chrome/browser/crash_report/breadcrumbs",
     "//ios/chrome/browser/credential_provider",
     "//ios/chrome/browser/device_sharing",
+    "//ios/chrome/browser/discover_feed",
     "//ios/chrome/browser/dom_distiller",
     "//ios/chrome/browser/download",
     "//ios/chrome/browser/favicon",

ios/chrome/browser/browser_state/browser_state_keyed_service_factories.mm

@@ -18,6 +18,7 @@
 #include "ios/chrome/browser/crash_report/breadcrumbs/breadcrumb_persistent_storage_keyed_service_factory.h"
 #include "ios/chrome/browser/credential_provider/credential_provider_service_factory.h"
 #import "ios/chrome/browser/device_sharing/device_sharing_manager_factory.h"
+#include "ios/chrome/browser/discover_feed/discover_feed_service_factory.h"
 #include "ios/chrome/browser/dom_distiller/dom_distiller_service_factory.h"
 #include "ios/chrome/browser/download/browser_download_service_factory.h"
 #include "ios/chrome/browser/favicon/favicon_service_factory.h"
@@ -108,6 +109,7 @@ void EnsureBrowserStateKeyedServiceFactoriesBuilt() {
   ConsentAuditorFactory::GetInstance();
   CredentialProviderServiceFactory::GetInstance();
   DeviceSharingManagerFactory::GetInstance();
+  DiscoverFeedServiceFactory::GetInstance();
   GoogleLogoServiceFactory::GetInstance();
   IdentityManagerFactory::GetInstance();
   IOSCookieBlockerFactory::GetInstance();

ios/chrome/browser/discover_feed/BUILD.gn

+# 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.
+
+source_set("discover_feed") {
+  configs += [ "//build/config/compiler:enable_arc" ]
+  sources = [
+    "discover_feed_service.h",
+    "discover_feed_service.mm",
+    "discover_feed_service_factory.h",
+    "discover_feed_service_factory.mm",
+  ]
+  deps = [
+    "//base",
+    "//components/autofill/core/common",
+    "//components/keyed_service/core",
+    "//components/keyed_service/ios",
+    "//components/signin/public/identity_manager",
+    "//ios/chrome/browser/browser_state",
+    "//ios/chrome/browser/signin",
+    "//ios/public/provider/chrome/browser",
+    "//ios/public/provider/chrome/browser/discover_feed",
+  ]
+}

ios/chrome/browser/discover_feed/OWNERS

+sczs@chromium.org
+gogerald@chromium.org
+
+# TEAM: ios-directory-owners@chromium.org
+# OS: iOS

ios/chrome/browser/discover_feed/discover_feed_service.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_DISCOVER_FEED_DISCOVER_FEED_SERVICE_H_
+#define IOS_CHROME_BROWSER_DISCOVER_FEED_DISCOVER_FEED_SERVICE_H_
+
+#include "components/keyed_service/core/keyed_service.h"
+#include "components/signin/public/identity_manager/identity_manager.h"
+
+class AuthenticationService;
+class DiscoverFeedProvider;
+
+// A browser-context keyed service that is used to keep the Discover Feed data
+// up to date.
+class DiscoverFeedService : public KeyedService,
+                            public signin::IdentityManager::Observer {
+ public:
+  // Initializes the service.
+  DiscoverFeedService(signin::IdentityManager* identity_manager,
+                      AuthenticationService* authentication_service,
+                      DiscoverFeedProvider* feed_provider);
+  ~DiscoverFeedService() override;
+
+  // KeyedService:
+  void Shutdown() override;
+
+ private:
+  // IdentityManager::Observer.
+  void OnPrimaryAccountSet(
+      const CoreAccountInfo& primary_account_info) override;
+  void OnPrimaryAccountCleared(
+      const CoreAccountInfo& previous_primary_account_info) override;
+
+  // Identity manager to observe.
+  signin::IdentityManager* identity_manager_;
+
+  // The AuthenticationService sent to DiscoverFeedProvider;
+  AuthenticationService* authentication_service_ = nullptr;
+
+  // Discover Feed provider to notify of changes.
+  DiscoverFeedProvider* discover_feed_provider_;
+
+  DISALLOW_COPY_AND_ASSIGN(DiscoverFeedService);
+};
+
+#endif  // IOS_CHROME_BROWSER_DISCOVER_FEED_DISCOVER_FEED_SERVICE_H_

ios/chrome/browser/discover_feed/discover_feed_service.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.
+
+#include "ios/chrome/browser/discover_feed/discover_feed_service.h"
+
+#import "ios/public/provider/chrome/browser/discover_feed/discover_feed_provider.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+DiscoverFeedService::DiscoverFeedService(
+    signin::IdentityManager* identity_manager,
+    AuthenticationService* authentication_service,
+    DiscoverFeedProvider* feed_provider)
+    : identity_manager_(identity_manager),
+      authentication_service_(authentication_service),
+      discover_feed_provider_(feed_provider) {
+  if (identity_manager_) {
+    identity_manager_->AddObserver(this);
+  }
+  discover_feed_provider_->StartFeed(authentication_service_);
+}
+
+DiscoverFeedService::~DiscoverFeedService() {}
+
+void DiscoverFeedService::Shutdown() {
+  if (identity_manager_) {
+    identity_manager_->RemoveObserver(this);
+  }
+}
+
+void DiscoverFeedService::OnPrimaryAccountSet(
+    const CoreAccountInfo& primary_account_info) {
+  discover_feed_provider_->UpdateFeedForAccountChange();
+}
+
+void DiscoverFeedService::OnPrimaryAccountCleared(
+    const CoreAccountInfo& previous_primary_account_info) {
+  discover_feed_provider_->UpdateFeedForAccountChange();
+}

ios/chrome/browser/discover_feed/discover_feed_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_DISCOVER_FEED_DISCOVER_FEED_SERVICE_FACTORY_H_
+#define IOS_CHROME_BROWSER_DISCOVER_FEED_DISCOVER_FEED_SERVICE_FACTORY_H_
+
+#include "base/no_destructor.h"
+#include "components/keyed_service/ios/browser_state_keyed_service_factory.h"
+
+class ChromeBrowserState;
+class DiscoverFeedService;
+
+// Singleton that owns all DiscoverFeedServices and associates them with
+// ChromeBrowserState.
+class DiscoverFeedServiceFactory : public BrowserStateKeyedServiceFactory {
+ public:
+  static DiscoverFeedService* GetForBrowserState(
+      ChromeBrowserState* browser_state);
+
+  static DiscoverFeedServiceFactory* GetInstance();
+
+ private:
+  friend class base::NoDestructor<DiscoverFeedServiceFactory>;
+
+  DiscoverFeedServiceFactory();
+  ~DiscoverFeedServiceFactory() override;
+
+  // BrowserStateKeyedServiceFactory implementation.
+  std::unique_ptr<KeyedService> BuildServiceInstanceFor(
+      web::BrowserState* context) const override;
+
+  DISALLOW_COPY_AND_ASSIGN(DiscoverFeedServiceFactory);
+};
+
+#endif  // IOS_CHROME_BROWSER_DISCOVER_FEED_DISCOVER_FEED_SERVICE_FACTORY_H_

ios/chrome/browser/discover_feed/discover_feed_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.
+
+#include "ios/chrome/browser/discover_feed/discover_feed_service_factory.h"
+
+#include "components/keyed_service/ios/browser_state_dependency_manager.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/discover_feed/discover_feed_service.h"
+#import "ios/chrome/browser/signin/authentication_service_factory.h"
+#include "ios/chrome/browser/signin/identity_manager_factory.h"
+#import "ios/public/provider/chrome/browser/chrome_browser_provider.h"
+#import "ios/public/provider/chrome/browser/discover_feed/discover_feed_provider.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+// static
+DiscoverFeedService* DiscoverFeedServiceFactory::GetForBrowserState(
+    ChromeBrowserState* browser_state) {
+  return static_cast<DiscoverFeedService*>(
+      GetInstance()->GetServiceForBrowserState(browser_state, true));
+}
+
+// static
+DiscoverFeedServiceFactory* DiscoverFeedServiceFactory::GetInstance() {
+  static base::NoDestructor<DiscoverFeedServiceFactory> instance;
+  return instance.get();
+}
+
+DiscoverFeedServiceFactory::DiscoverFeedServiceFactory()
+    : BrowserStateKeyedServiceFactory(
+          "DiscoverFeedService",
+          BrowserStateDependencyManager::GetInstance()) {
+  DependsOn(AuthenticationServiceFactory::GetInstance());
+  DependsOn(IdentityManagerFactory::GetInstance());
+}
+
+DiscoverFeedServiceFactory::~DiscoverFeedServiceFactory() = default;
+
+std::unique_ptr<KeyedService>
+DiscoverFeedServiceFactory::BuildServiceInstanceFor(
+    web::BrowserState* context) const {
+  ChromeBrowserState* browser_state =
+      ChromeBrowserState::FromBrowserState(context);
+  signin::IdentityManager* identity_manager =
+      IdentityManagerFactory::GetForBrowserState(browser_state);
+  AuthenticationService* authentication_service =
+      AuthenticationServiceFactory::GetForBrowserState(browser_state);
+
+  return std::make_unique<DiscoverFeedService>(
+      identity_manager, authentication_service,
+      ios::GetChromeBrowserProvider()->GetDiscoverFeedProvider());
+}

ios/chrome/browser/ui/content_suggestions/BUILD.gn

@@ -48,6 +48,7 @@ source_set("content_suggestions") {
     "//ios/chrome/app/strings",
     "//ios/chrome/browser",
     "//ios/chrome/browser/browser_state",
+    "//ios/chrome/browser/discover_feed",
     "//ios/chrome/browser/drag_and_drop",
     "//ios/chrome/browser/favicon",
     "//ios/chrome/browser/main:public",

ios/chrome/browser/ui/content_suggestions/content_suggestions_coordinator.mm

@@ -15,6 +15,7 @@
 #include "components/ntp_tiles/most_visited_sites.h"
 #include "components/prefs/pref_service.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/discover_feed/discover_feed_service_factory.h"
 #include "ios/chrome/browser/drag_and_drop/drag_and_drop_flag.h"
 #import "ios/chrome/browser/drag_and_drop/url_drag_drop_handler.h"
 #include "ios/chrome/browser/favicon/ios_chrome_large_icon_cache_factory.h"
@@ -197,6 +198,11 @@
       ReadingListModelFactory::GetForBrowserState(
           self.browser->GetBrowserState());
 
+  if (IsDiscoverFeedEnabled()) {
+    // Creating the DiscoverFeedService will start the DiscoverFeed.
+    DiscoverFeedServiceFactory::GetForBrowserState(
+        self.browser->GetBrowserState());
+  }
   self.discoverFeedViewController = [self discoverFeed];
 
   self.contentSuggestionsMediator = [[ContentSuggestionsMediator alloc]

ios/public/provider/chrome/browser/discover_feed/discover_feed_provider.h

@@ -7,9 +7,8 @@
 
 #import <UIKit/UIKit.h>
 
-#include "base/ios/block_types.h"
-
 @protocol ApplicationCommands;
+class AuthenticationService;
 class Browser;
 
 // DiscoverFeedProvider allows embedders to provide functionality for a Discover
@@ -35,6 +34,8 @@ class DiscoverFeedProvider {
   DiscoverFeedProvider(const DiscoverFeedProvider&) = delete;
   DiscoverFeedProvider& operator=(const DiscoverFeedProvider&) = delete;
 
+  // Starts the Feed using |auth_service| to check if user is Signed In/Out.
+  virtual void StartFeed(AuthenticationService* auth_service);
   // Returns true if the Discover Feed is enabled.
   virtual bool IsDiscoverFeedEnabled();
   // Returns the Discover Feed ViewController.
@@ -45,9 +46,8 @@ class DiscoverFeedProvider {
   // Refreshes the Discover Feed. Once the Feed model is refreshed it will
   // update all ViewControllers returned by NewFeedViewController.
   virtual void RefreshFeed();
-  // DEPRECATED. Delete once https://crrev.com/i/3205705 lands, along
-  // base/ios/block_types.h
-  virtual void RefreshFeedWithCompletion(ProceduralBlock completion);
+  // Updates the Feed for an account change e.g. Signing In/Out.
+  virtual void UpdateFeedForAccountChange();
   // Methods to register or remove observers.
   virtual void AddObserver(Observer* observer);
   virtual void RemoveObserver(Observer* observer);

ios/public/provider/chrome/browser/discover_feed/discover_feed_provider.mm

@@ -8,6 +8,8 @@
 #error "This file requires ARC support."
 #endif
 
+void DiscoverFeedProvider::StartFeed(AuthenticationService* auth_service) {}
+
 bool DiscoverFeedProvider::IsDiscoverFeedEnabled() {
   return false;
 }
@@ -20,8 +22,8 @@ UIViewController* DiscoverFeedProvider::NewFeedViewController(
 void DiscoverFeedProvider::UpdateTheme() {}
 
 void DiscoverFeedProvider::RefreshFeed() {}
-void DiscoverFeedProvider::RefreshFeedWithCompletion(
-    ProceduralBlock completion) {}
+
+void DiscoverFeedProvider::UpdateFeedForAccountChange() {}
 
 void DiscoverFeedProvider::AddObserver(Observer* observer) {}
 void DiscoverFeedProvider::RemoveObserver(Observer* observer) {}