Adopt base::NoDestructor for KeyedService factories

For changes under /chrome/browser/badging

It replaces base::Singleton, following the latest recommendation
in base/ and browser_context_keyed_service_factory.h.

For factories with a trivial destructor, it makes no difference.

LSC doc:
https://docs.google.com/document/d/1x1LqRQyfBOmpMkNQBYs7QBPSxLtuiImvmgcJYI_kaS4/edit?usp=sharing

This CL was uploaded by git cl split.

R=cmp@chromium.org

Bug: 925323
Change-Id: I268eabeeccd3d27b04b5ba322c2811e2500a28c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4568013
Reviewed-by: Chase Phillips <cmp@chromium.org>
Auto-Submit: Mikel Astiz <mastiz@chromium.org>
Commit-Queue: Chase Phillips <cmp@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1150321}

chrome/browser/badging/badge_manager_factory.cc

@@ -8,7 +8,7 @@
 
 #include "base/functional/bind.h"
 #include "base/memory/ptr_util.h"
-#include "base/memory/singleton.h"
+#include "base/no_destructor.h"
 #include "chrome/browser/badging/badge_manager.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/web_applications/web_app_provider_factory.h"
@@ -24,7 +24,8 @@ BadgeManager* BadgeManagerFactory::GetForProfile(Profile* profile) {
 
 // static
 BadgeManagerFactory* BadgeManagerFactory::GetInstance() {
-  return base::Singleton<BadgeManagerFactory>::get();
+  static base::NoDestructor<BadgeManagerFactory> instance;
+  return instance.get();
 }
 
 BadgeManagerFactory::BadgeManagerFactory()
@@ -39,7 +40,7 @@ BadgeManagerFactory::BadgeManagerFactory()
   DependsOn(web_app::WebAppProviderFactory::GetInstance());
 }
 
-BadgeManagerFactory::~BadgeManagerFactory() {}
+BadgeManagerFactory::~BadgeManagerFactory() = default;
 
 KeyedService* BadgeManagerFactory::BuildServiceInstanceFor(
     content::BrowserContext* context) const {

chrome/browser/badging/badge_manager_factory.h

@@ -9,7 +9,7 @@
 
 namespace base {
 template <typename T>
-struct DefaultSingletonTraits;
+class NoDestructor;
 }
 
 class Profile;
@@ -32,7 +32,7 @@ class BadgeManagerFactory : public ProfileKeyedServiceFactory {
   BadgeManagerFactory& operator=(const BadgeManagerFactory&) = delete;
 
  private:
-  friend struct base::DefaultSingletonTraits<BadgeManagerFactory>;
+  friend base::NoDestructor<BadgeManagerFactory>;
 
   BadgeManagerFactory();
   ~BadgeManagerFactory() override;