Add ContentSuggestionsMediator

ios/chrome/browser/content_suggestions/content_suggestions_service_bridge_observer.mm

+// Copyright 2017 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/content_suggestions/content_suggestions_service_bridge_observer.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+ContentSuggestionsServiceBridge::ContentSuggestionsServiceBridge(
+    id<ContentSuggestionsServiceObserver> observer,
+    ntp_snippets::ContentSuggestionsService* service) {
+  observer_ = observer;
+  service_ = service;
+  service->AddObserver(this);
+}
+
+ContentSuggestionsServiceBridge::~ContentSuggestionsServiceBridge() {
+  service_->RemoveObserver(this);
+}
+
+void ContentSuggestionsServiceBridge::OnNewSuggestions(
+    ntp_snippets::Category category) {
+  [observer_ contentSuggestionsService:service_
+              newSuggestionsInCategory:category];
+}
+
+void ContentSuggestionsServiceBridge::OnCategoryStatusChanged(
+    ntp_snippets::Category category,
+    ntp_snippets::CategoryStatus new_status) {
+  [observer_ contentSuggestionsService:service_
+                              category:category
+                       statusChangedTo:new_status];
+}
+
+void ContentSuggestionsServiceBridge::OnSuggestionInvalidated(
+    const ntp_snippets::ContentSuggestion::ID& suggestion_id) {
+  [observer_ contentSuggestionsService:service_
+                 SuggestionInvalidated:suggestion_id];
+}
+
+void ContentSuggestionsServiceBridge::OnFullRefreshRequired() {
+  [observer_ contentSuggestionsServiceFullRefreshRequired:service_];
+}
+
+void ContentSuggestionsServiceBridge::ContentSuggestionsServiceShutdown() {
+  [observer_ contentSuggestionsServiceShutdown:service_];
+}