[TaskEnvironment] Mass-migrate away from ScopedTaskEnvironment

(second half of
 https://chromium-review.googlesource.com/c/chromium/src/+/1756247)

This is step #1 of the mass migration. Some of these will be
backported to SingleThreadTaskEnvironment in a later phase.

scoped_task_environment.h will also only move in a follow-up CL.

[email protected]

Bug: 992483
Change-Id: Ie80f083eeeb209180ab3c2884f1b566f73549cc6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1756248
Reviewed-by: Gabriel Charette <[email protected]>
Reviewed-by: Daniel Cheng <[email protected]>
Commit-Queue: Gabriel Charette <[email protected]>
Cr-Commit-Position: refs/heads/master@{#688142}
diff --git a/components/prefs/persistent_pref_store_unittest.cc b/components/prefs/persistent_pref_store_unittest.cc
index d297858..fe9a418 100644
--- a/components/prefs/persistent_pref_store_unittest.cc
+++ b/components/prefs/persistent_pref_store_unittest.cc
@@ -12,7 +12,7 @@
 
 void TestCommitPendingWriteWithCallback(
     PersistentPrefStore* store,
-    base::test::ScopedTaskEnvironment* scoped_task_environment) {
+    base::test::TaskEnvironment* task_environment) {
   base::RunLoop run_loop;
   base::SequenceCheckerImpl sequence_checker;
   store->CommitPendingWrite(base::BindOnce(
@@ -21,6 +21,6 @@
         run_loop->Quit();
       },
       base::Unretained(&sequence_checker), base::Unretained(&run_loop)));
-  scoped_task_environment->RunUntilIdle();
+  task_environment->RunUntilIdle();
   run_loop.Run();
 }