Create an Obj-C bridge for MostVisitedSitesObserver

ios/chrome/browser/ntp_tiles/most_visited_sites_observer_bridge.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/ntp_tiles/most_visited_sites_observer_bridge.h"
+
+namespace ntp_tiles {
+
+MostVisitedSitesObserverBridge::MostVisitedSitesObserverBridge(
+    id<MostVisitedSitesObserving> observer) {
+  observer_.reset(observer);
+}
+
+MostVisitedSitesObserverBridge::~MostVisitedSitesObserverBridge() {}
+
+void MostVisitedSitesObserverBridge::OnMostVisitedURLsAvailable(
+    const NTPTilesVector& most_visited) {
+  [observer_ onMostVisitedURLsAvailable:most_visited];
+}
+
+void MostVisitedSitesObserverBridge::OnIconMadeAvailable(const GURL& site_url) {
+  [observer_ onIconMadeAvailable:site_url];
+}
+
+}  // namespace ntp_tiles