Migrate upgrade notifications to observer

chrome/browser/service_process/service_process_control.cc

Index: chrome/browser/service_process/service_process_control.cc
diff --git a/chrome/browser/service_process/service_process_control.cc b/chrome/browser/service_process/service_process_control.cc
index c0499002c0ced58eab560da8226a7e7f9893f41d..2df31951c439bd0074b980195f5610ac6706cea5 100644
--- a/chrome/browser/service_process/service_process_control.cc
+++ b/chrome/browser/service_process/service_process_control.cc
@@ -25,12 +25,10 @@
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
-#include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/upgrade_detector.h"
 #include "chrome/common/service_messages.h"
 #include "chrome/common/service_process_util.h"
 #include "content/public/browser/browser_thread.h"
-#include "content/public/browser/notification_service.h"
 #include "ipc/ipc_channel_mojo.h"
 #include "mojo/edk/embedder/embedder.h"
 #include "mojo/edk/embedder/named_platform_handle.h"
@@ -87,9 +85,12 @@ void ConnectAsyncWithBackoff(
 }  // namespace
 
 // ServiceProcessControl implementation.
-ServiceProcessControl::ServiceProcessControl() : weak_factory_(this) {}
+ServiceProcessControl::ServiceProcessControl() : weak_factory_(this) {
+  UpgradeDetector::GetInstance()->AddObserver(this);
+}
 
 ServiceProcessControl::~ServiceProcessControl() {
+  UpgradeDetector::GetInstance()->RemoveObserver(this);
 }
 
 void ServiceProcessControl::ConnectInternal() {
@@ -244,10 +245,6 @@ void ServiceProcessControl::OnChannelConnected(int32_t peer_pid) {
   // upgrade is available.
   if (UpgradeDetector::GetInstance()->notify_upgrade()) {
     Send(new ServiceMsg_UpdateAvailable);
-  } else {
-    if (registrar_.IsEmpty())
-      registrar_.Add(this, chrome::NOTIFICATION_UPGRADE_RECOMMENDED,
-                     content::NotificationService::AllSources());
   }
   RunConnectDoneTasks();
 }
@@ -270,12 +267,7 @@ bool ServiceProcessControl::Send(IPC::Message* message) {
   return channel_->Send(message);
 }
 
-// content::NotificationObserver implementation.
-void ServiceProcessControl::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
-  DCHECK_EQ(chrome::NOTIFICATION_UPGRADE_RECOMMENDED, type);

[sky, 2017/06/07 23:01:41]

Previously the observer was only added in a certain cases. Don't you need to
protect against that? By that I mean either set some boolean around line 248
(old) or conditionally add the observer?

[weidongg, 2017/06/08 02:28:42]

This function will be called multiple times. So I added a
|enable_upgrade_observer_| to prevent duplicate adding observer.

+void ServiceProcessControl::OnUpgradeRecommended() {
   Send(new ServiceMsg_UpdateAvailable);
 }