Retire ScopedObserver in /components/safe_browsing.

ScopedObserver is being deprecated in favor of two new classes:
- base::ScopedObservation for observers that only ever observe
  a single source.
- base::ScopedMultiSourceObservation for observers that do or may
  observe more than a single source.

This CL was uploaded by git cl split.

R=drubery@chromium.org

Bug: 1145565
Change-Id: Id8d8c10f96b678c33a07d9526a3dc495db69f356
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2532721
Auto-Submit: Sigurður Ásgeirsson <siggi@chromium.org>
Reviewed-by: Daniel Rubery <drubery@chromium.org>
Commit-Queue: Daniel Rubery <drubery@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826566}

components/safe_browsing/content/browser/threat_details_history.cc

@@ -24,7 +24,7 @@ ThreatDetailsRedirectsCollector::ThreatDetailsRedirectsCollector(
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   if (history_service) {
-    history_service_observer_.Add(history_service.get());
+    history_service_observation_.Observe(history_service.get());
   }
 }
 
@@ -111,7 +111,8 @@ void ThreatDetailsRedirectsCollector::AllDone() {
 
 void ThreatDetailsRedirectsCollector::HistoryServiceBeingDeleted(
     history::HistoryService* history_service) {
-  history_service_observer_.Remove(history_service);
+  DCHECK(history_service_observation_.IsObservingSource(history_service));
+  history_service_observation_.RemoveObservation();
   history_service_.reset();
 }
 

components/safe_browsing/content/browser/threat_details_history.h

@@ -13,7 +13,7 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/scoped_observer.h"
+#include "base/scoped_observation.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "components/history/core/browser/history_service.h"
@@ -76,8 +76,9 @@ class ThreatDetailsRedirectsCollector
   std::vector<RedirectChain> redirects_urls_;
 
   base::WeakPtr<history::HistoryService> history_service_;
-  ScopedObserver<history::HistoryService, history::HistoryServiceObserver>
-      history_service_observer_{this};
+  base::ScopedObservation<history::HistoryService,
+                          history::HistoryServiceObserver>
+      history_service_observation_{this};
 
   DISALLOW_COPY_AND_ASSIGN(ThreatDetailsRedirectsCollector);
 };

components/safe_browsing/core/verdict_cache_manager.cc

@@ -372,7 +372,7 @@ VerdictCacheManager::VerdictCacheManager(
       stored_verdict_count_real_time_url_check_(base::nullopt),
       content_settings_(content_settings) {
   if (history_service)
-    history_service_observer_.Add(history_service);
+    history_service_observation_.Observe(history_service);
   if (!content_settings->IsOffTheRecord()) {
     ScheduleNextCleanUpAfterInterval(
         base::TimeDelta::FromSeconds(kCleanUpIntervalInitSecond));
@@ -382,7 +382,8 @@ VerdictCacheManager::VerdictCacheManager(
 
 void VerdictCacheManager::Shutdown() {
   CleanUpExpiredVerdicts();
-  history_service_observer_.RemoveAll();
+  if (history_service_observation_.IsObserving())
+    history_service_observation_.RemoveObservation();
   weak_factory_.InvalidateWeakPtrs();
 }
 
@@ -688,7 +689,8 @@ void VerdictCacheManager::OnURLsDeleted(
 // Overridden from history::HistoryServiceObserver.
 void VerdictCacheManager::HistoryServiceBeingDeleted(
     history::HistoryService* history_service) {
-  history_service_observer_.Remove(history_service);
+  DCHECK(history_service_observation_.IsObservingSource(history_service));
+  history_service_observation_.RemoveObservation();
 }
 
 bool VerdictCacheManager::RemoveExpiredPhishGuardVerdicts(

components/safe_browsing/core/verdict_cache_manager.h

@@ -8,7 +8,7 @@
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_refptr.h"
 #include "base/memory/weak_ptr.h"
-#include "base/scoped_observer.h"
+#include "base/scoped_observation.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "base/values.h"
@@ -156,8 +156,9 @@ class VerdictCacheManager : public history::HistoryServiceObserver,
   // Number of verdict stored for this profile for real time url check pings.
   base::Optional<size_t> stored_verdict_count_real_time_url_check_;
 
-  ScopedObserver<history::HistoryService, history::HistoryServiceObserver>
-      history_service_observer_{this};
+  base::ScopedObservation<history::HistoryService,
+                          history::HistoryServiceObserver>
+      history_service_observation_{this};
 
   // Content settings maps associated with this instance.
   scoped_refptr<HostContentSettingsMap> content_settings_;