Revert of Tests: Simplify SequencedWorkerPoolOwner, call Shutdown on destructor. (patchset #4 id:60001 of https://codereview.chromium.org/1417353006/ )

Reason for revert:
Suspected for persistent failures on ios_net_unittests

- RoundTripTestCookieStore/CookieStoreTest/0.TestNonDottedAndTLD
- CookieStoreIOS/CookieStoreTest/0.TestNonDottedAndTLD

Failing since https://build.chromium.org/p/chromium.mac/builders/iOS_Simulator_%28dbg%29/builds/32876

Errors like

../../net/cookies/cookie_store_unittest.h:536: Failure
Value of: this->SetCookie(cs.get(), url, "a=1; domain=com")
  Actual: false
Expected: true

(It's a tricky one! Sorry if this is not it)

Original issue's description:
> Tests: Simplify SequencedWorkerPoolOwner, call Shutdown on destructor.
>
> Also ports remaining tests using raw SWPs to use SWPOwner.
>
> BUG=450228
>
> Committed: https://crrev.com/fc939726c283e34112d9bc845a39460410fe9cd9
> Cr-Commit-Position: refs/heads/master@{#362805}

TBR=phajdan.jr@chromium.org,jam@chromium.org,brettw@chromium.org,tommycli@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=450228

Review URL: https://codereview.chromium.org/1496493004

Cr-Commit-Position: refs/heads/master@{#362890}

1 files changed, 1 insertions, 0 deletions

diff --git a/components/component_updater/component_updater_service_unittest.cc b/components/component_updater/component_updater_service_unittest.cc
index a5a839d..9d78eb8 100644
--- a/components/component_updater/component_updater_service_unittest.cc
+++ b/components/component_updater/component_updater_service_unittest.cc
@@ -174,6 +174,7 @@ ComponentUpdaterTest::ComponentUpdaterTest()
 
 ComponentUpdaterTest::~ComponentUpdaterTest() {
   EXPECT_CALL(update_client(), RemoveObserver(_)).Times(1);
+  worker_pool_->pool()->Shutdown();
   component_updater_.reset();
 }