[NTP::Push] Adding BreakingNewsSuggestionsProvider

components/ntp_snippets/breaking_news/content_suggestions_gcm_app_handler.cc

 // 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.
 
 #include "components/ntp_snippets/breaking_news/content_suggestions_gcm_app_handler.h"
 
 #include "base/strings/string_util.h"
 #include "components/gcm_driver/gcm_driver.h"
 #include "components/gcm_driver/gcm_profile_service.h"
 #include "components/gcm_driver/instance_id/instance_id.h"
@@ skipping 22 matching lines @@
     : gcm_driver_(gcm_driver),
       instance_id_driver_(instance_id_driver),
       pref_service_(pref_service),
       subscription_manager_(std::move(subscription_manager)),
       weak_factory_(this) {}
 
 ContentSuggestionsGCMAppHandler::~ContentSuggestionsGCMAppHandler() {
   StopListening();
 }
 
-void ContentSuggestionsGCMAppHandler::StartListening() {
+void ContentSuggestionsGCMAppHandler::StartListening(
+    OnNewContentCallback on_new_content_callback) {
 #if !defined(OS_ANDROID)
   NOTREACHED()
       << "The ContentSuggestionsGCMAppHandler should only be used on Android.";
 #endif
   Subscribe();
+  on_new_content_callback_ = std::move(on_new_content_callback);
   gcm_driver_->AddAppHandler(kContentSuggestionsGCMAppID, this);
 }
 
 void ContentSuggestionsGCMAppHandler::StopListening() {
   DCHECK_EQ(gcm_driver_->GetAppHandler(kContentSuggestionsGCMAppID), this);
   gcm_driver_->RemoveAppHandler(kContentSuggestionsGCMAppID);
+  on_new_content_callback_ = OnNewContentCallback();
   std::string token = pref_service_->GetString(
       ntp_snippets::prefs::kContentSuggestionsGCMSubscriptionTokenCache);
   subscription_manager_->Unsubscribe(token);
 }
 
 void ContentSuggestionsGCMAppHandler::Subscribe() {
   std::string token = pref_service_->GetString(
       ntp_snippets::prefs::kContentSuggestionsGCMSubscriptionTokenCache);
   if (!token.empty()) {
     return;
@@ skipping 33 matching lines @@
 void ContentSuggestionsGCMAppHandler::ShutdownHandler() {}
 
 void ContentSuggestionsGCMAppHandler::OnStoreReset() {
   pref_service_->ClearPref(
       ntp_snippets::prefs::kContentSuggestionsGCMSubscriptionTokenCache);
 }
 
 void ContentSuggestionsGCMAppHandler::OnMessage(
     const std::string& app_id,
     const gcm::IncomingMessage& message) {
-  // TODO(mamir): Implement Show notification and update the feed.
+  // TODO(mamir): Build the message.
+  on_new_content_callback_.Run(base::Value());

[jkrcal, 2017/06/09 11:32:59]

Are you sure this will never get called after StopListening deletes
on_new_content_callback?

Maybe DCHECK(on_new_content_callback)?

[mamir, 2017/06/09 14:41:01]

Yes, this won't be called after StopListening because the handler will be
removed upon calling StopListening and before deleting on_new_content_callback.

 }
 
 void ContentSuggestionsGCMAppHandler::OnMessagesDeleted(
     const std::string& app_id) {
   // Messages don't get deleted.
   NOTREACHED() << "ContentSuggestionsGCMAppHandler messages don't get deleted.";
 }
 
 void ContentSuggestionsGCMAppHandler::OnSendError(
     const std::string& app_id,
@@ skipping 11 matching lines @@
   NOTREACHED() << "ContentSuggestionsGCMAppHandler doesn't send GCM messages.";
 }
 
 void ContentSuggestionsGCMAppHandler::RegisterProfilePrefs(
     PrefRegistrySimple* registry) {
   registry->RegisterStringPref(
       prefs::kContentSuggestionsGCMSubscriptionTokenCache, std::string());
 }
 
 }  // namespace ntp_snippets