[CodeHealth][rewards] Use base::ScopedObservation pt.2

This PR changes the use of manual `raw_ptr` for observations, to have
then managed by `base::ScopedObservation`.

Resolves brave/brave-browser#41607

browser/brave_rewards/android/brave_rewards_native_worker.cc

@@ -42,19 +42,18 @@ namespace android {
 BraveRewardsNativeWorker::BraveRewardsNativeWorker(JNIEnv* env,
     const base::android::JavaRef<jobject>& obj):
     weak_java_brave_rewards_native_worker_(env, obj),
-    brave_rewards_service_(nullptr),
     weak_factory_(this) {
   Java_BraveRewardsNativeWorker_setNativePtr(env, obj,
     reinterpret_cast<intptr_t>(this));
 
   brave_rewards_service_ = brave_rewards::RewardsServiceFactory::GetForProfile(
       ProfileManager::GetActiveUserProfile()->GetOriginalProfile());
   if (brave_rewards_service_) {
-    brave_rewards_service_->AddObserver(this);
-    brave_rewards::RewardsNotificationService* notification_service =
-      brave_rewards_service_->GetNotificationService();
-    if (notification_service) {
-      notification_service->AddObserver(this);
+    rewards_service_observation_.Observe(brave_rewards_service_);
+
+    if (auto* notification_service =
+            brave_rewards_service_->GetNotificationService()) {
+      rewards_notification_service_observation_.Observe(notification_service);
     }
   }
 }
@@ -63,14 +62,6 @@ BraveRewardsNativeWorker::~BraveRewardsNativeWorker() {
 }
 
 void BraveRewardsNativeWorker::Destroy(JNIEnv* env) {
-  if (brave_rewards_service_) {
-    brave_rewards_service_->RemoveObserver(this);
-    brave_rewards::RewardsNotificationService* notification_service =
-      brave_rewards_service_->GetNotificationService();
-    if (notification_service) {
-      notification_service->RemoveObserver(this);
-    }
-  }
   delete this;
 }
 
@@ -251,8 +242,8 @@ void BraveRewardsNativeWorker::GetPublisherInfo(
     int tabId,
     const base::android::JavaParamRef<jstring>& host) {
   if (brave_rewards_service_) {
-    brave_rewards_service_->GetPublisherActivityFromUrl(tabId,
-      base::android::ConvertJavaStringToUTF8(env, host), "", "");
+    brave_rewards_service_->GetPublisherActivityFromUrl(
+        tabId, base::android::ConvertJavaStringToUTF8(env, host), "", "");
   }
 }
 
@@ -578,26 +569,16 @@ void BraveRewardsNativeWorker::OnSendContribution(bool result) {
 }
 
 void BraveRewardsNativeWorker::GetAllNotifications(JNIEnv* env) {
-  if (!brave_rewards_service_) {
-    return;
-  }
-  brave_rewards::RewardsNotificationService* notification_service =
-    brave_rewards_service_->GetNotificationService();
-  if (notification_service) {
-    notification_service->GetNotifications();
+  if (rewards_notification_service_observation_.IsObserving()) {
+    rewards_notification_service_observation_.GetSource()->GetNotifications();
   }
 }
 
 void BraveRewardsNativeWorker::DeleteNotification(JNIEnv* env,
         const base::android::JavaParamRef<jstring>& notification_id) {
-  if (!brave_rewards_service_) {
-    return;
-  }
-  brave_rewards::RewardsNotificationService* notification_service =
-    brave_rewards_service_->GetNotificationService();
-  if (notification_service) {
-    notification_service->DeleteNotification(
-      base::android::ConvertJavaStringToUTF8(env, notification_id));
+  if (rewards_notification_service_observation_.IsObserving()) {
+    rewards_notification_service_observation_.GetSource()->DeleteNotification(
+        base::android::ConvertJavaStringToUTF8(env, notification_id));
   }
 }
 
@@ -704,14 +685,14 @@ double BraveRewardsNativeWorker::GetPublisherRecurrentDonationAmount(
 void BraveRewardsNativeWorker::RemoveRecurring(JNIEnv* env,
     const base::android::JavaParamRef<jstring>& publisher) {
   if (brave_rewards_service_) {
-      brave_rewards_service_->RemoveRecurringTip(
+    brave_rewards_service_->RemoveRecurringTip(
+        base::android::ConvertJavaStringToUTF8(env, publisher));
+    auto it = map_recurrent_publishers_.find(
         base::android::ConvertJavaStringToUTF8(env, publisher));
-      auto it = map_recurrent_publishers_.find(
-          base::android::ConvertJavaStringToUTF8(env, publisher));
 
-      if (it != map_recurrent_publishers_.end()) {
-        map_recurrent_publishers_.erase(it);
-      }
+    if (it != map_recurrent_publishers_.end()) {
+      map_recurrent_publishers_.erase(it);
+    }
   }
 }
 

browser/brave_rewards/android/brave_rewards_native_worker.h

@@ -7,6 +7,7 @@
 #define BRAVE_BROWSER_BRAVE_REWARDS_ANDROID_BRAVE_REWARDS_NATIVE_WORKER_H_
 
 #include <jni.h>
+
 #include <map>
 #include <memory>
 #include <string>
@@ -16,6 +17,7 @@
 #include "base/containers/flat_map.h"
 #include "base/memory/raw_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "base/scoped_observation.h"
 #include "brave/components/brave_ads/core/mojom/brave_ads.mojom.h"
 #include "brave/components/brave_rewards/browser/rewards_notification_service_observer.h"
 #include "brave/components/brave_rewards/browser/rewards_service_observer.h"
@@ -273,6 +275,12 @@ class BraveRewardsNativeWorker
   std::map<std::string, brave_rewards::mojom::PublisherInfoPtr>
       map_recurrent_publishers_;
   std::map<std::string, std::string> addresses_;
+  base::ScopedObservation<brave_rewards::RewardsService,
+                          brave_rewards::RewardsServiceObserver>
+      rewards_service_observation_{this};
+  base::ScopedObservation<brave_rewards::RewardsNotificationService,
+                          brave_rewards::RewardsNotificationServiceObserver>
+      rewards_notification_service_observation_{this};
   base::WeakPtrFactory<BraveRewardsNativeWorker> weak_factory_;
 };
 

browser/brave_rewards/rewards_tab_helper.cc

@@ -55,10 +55,9 @@ RewardsTabHelper::RewardsTabHelper(content::WebContents* web_contents)
   if (tab_id_.is_valid()) {
     rewards_service_ = RewardsServiceFactory::GetForProfile(
         Profile::FromBrowserContext(GetWebContents().GetBrowserContext()));
-  }
-
-  if (rewards_service_) {
-    rewards_service_->AddObserver(this);
+    if (rewards_service_) {
+      rewards_service_observation_.Observe(rewards_service_);
+    }
   }
 
 #if !BUILDFLAG(IS_ANDROID)
@@ -67,9 +66,6 @@ RewardsTabHelper::RewardsTabHelper(content::WebContents* web_contents)
 }
 
 RewardsTabHelper::~RewardsTabHelper() {
-  if (rewards_service_) {
-    rewards_service_->RemoveObserver(this);
-  }
 #if !BUILDFLAG(IS_ANDROID)
   BrowserList::RemoveObserver(browser_list_observer_.get());
 #endif
@@ -186,10 +182,8 @@ void RewardsTabHelper::OnRewardsInitialized(RewardsService* rewards_service) {
   // When Rewards is initialized for the current profile, we need to inform the
   // utility process about the currently active tab so that it can start
   // measuring auto-contribute correctly.
-  if (rewards_service_) {
-    rewards_service_->OnShow(tab_id_);
-    rewards_service_->OnLoad(tab_id_, GetWebContents().GetLastCommittedURL());
-  }
+  rewards_service->OnShow(tab_id_);
+  rewards_service->OnLoad(tab_id_, GetWebContents().GetLastCommittedURL());
 }
 
 void RewardsTabHelper::MaybeSavePublisherInfo() {

browser/brave_rewards/rewards_tab_helper.h

@@ -89,7 +89,10 @@ class RewardsTabHelper : public content::WebContentsUserData<RewardsTabHelper>,
   std::unique_ptr<BrowserListObserver> browser_list_observer_;
 #endif
   SessionID tab_id_;
-  raw_ptr<RewardsService> rewards_service_ = nullptr;  // NOT OWNED
+  base::ScopedObservation<brave_rewards::RewardsService,
+                          brave_rewards::RewardsServiceObserver>
+      rewards_service_observation_{this};
+  raw_ptr<RewardsService> rewards_service_ = nullptr;
   base::ObserverList<Observer> observer_list_;
   std::string publisher_id_;