Introduce ThreadTaskRunnerHandle::OverrideForTesting and TestMockTimeTaskRunner::ScopedContext.

components/password_manager/core/browser/affiliated_match_helper.h

Index: components/password_manager/core/browser/affiliated_match_helper.h
diff --git a/components/password_manager/core/browser/affiliated_match_helper.h b/components/password_manager/core/browser/affiliated_match_helper.h
index 7e51c9611c1a5f695e4b7400355c8197518ac7df..50c7fd2d544445f28182a196e198bf6227fc8fb6 100644
--- a/components/password_manager/core/browser/affiliated_match_helper.h
+++ b/components/password_manager/core/browser/affiliated_match_helper.h
@@ -5,8 +5,6 @@
 #ifndef COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATED_MATCH_HELPER_H_
 #define COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATED_MATCH_HELPER_H_
 
-#include <stdint.h>
-
 #include <memory>
 #include <string>
 #include <vector>
@@ -14,6 +12,7 @@
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/time/time.h"
 #include "components/password_manager/core/browser/affiliation_utils.h"
 #include "components/password_manager/core/browser/password_store.h"
 #include "components/password_manager/core/browser/password_store_consumer.h"
@@ -100,17 +99,13 @@ class AffiliatedMatchHelper : public PasswordStore::Observer,
   // purposes of affiliation-based matching.
   static bool IsValidWebCredential(const PasswordStore::FormDigest& form);
 
-  // Sets the task runner to be used to delay I/O heavy initialization. Should
-  // be called before Initialize(). Used only for testing.
-  void SetTaskRunnerUsedForWaitingForTesting(
-      const scoped_refptr<base::SingleThreadTaskRunner> task_runner);
-
   // I/O heavy initialization on start-up will be delayed by this long.
   // This should be high enough not to exacerbate start-up I/O contention too
   // much, but also low enough that the user be able log-in shortly after
   // browser start-up into web sites using Android credentials.
   // TODO(engedy): See if we can tie this instead to some meaningful event.
-  static const int64_t kInitializationDelayOnStartupInSeconds = 8;
+  static constexpr base::TimeDelta kInitializationDelayOnStartup =
+      base::TimeDelta::FromSeconds(8);
 
  private:
   // Reads all autofillable credentials from the password store and starts