Fix use-after-move in //components/signin/public/identity_manager/

Fix use-after-move (potential) bugs found by the
"bugprone-use-after-move" clang-tidy check.

Bug: 1122844
Change-Id: I6859b6c96a35f6f9c06e7d8d73db5251379531ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2382076Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#802958}

components/signin/public/identity_manager/identity_manager_unittest.cc

@@ -1313,7 +1313,9 @@ TEST_F(IdentityManagerTest,
       account_tracker()->FindAccountInfoByGaiaId(kTestGaiaId2).account_id;
   UpdateCredentials(account_id2, kTestGaiaId2, kTestEmail2, "refresh_token");
 
-  // No changes to the declared scopes and callback, we can reuse them.
+  // No changes to the declared scopes, we can reuse it.
+  callback = base::BindOnce(
+      [](GoogleServiceAuthError error, AccessTokenInfo access_token_info) {});
   std::unique_ptr<AccessTokenFetcher> token_fetcher2 =
       identity_manager()->CreateAccessTokenFetcherForAccount(
           account_id2, kTestConsumerId2, scopes, std::move(callback),