Cookie Store: Remove instance name from unittests.

This CL removes a redundant "CookieStoreManagerTest/" prefix from all
unit test names. For example,
CookieStoreManagerTest/CookieStoreManagerTest.OneCookieChange/0 becomes
CookieStoreManagerTest.OneCookieChange/0.

Change-Id: I9f07ad0c322c55a7d26e5d02a16fb52aa1350844
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1844152
Auto-Submit: Victor Costan <pwnall@chromium.org>
Reviewed-by: Staphany Park <staphany@chromium.org>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703470}

content/browser/cookie_store/cookie_store_manager_unittest.cc

@@ -968,7 +968,7 @@ TEST_P(CookieStoreManagerTest, GetSubscriptionsFromWrongOrigin) {
   EXPECT_FALSE(wrong_subscriptions_opt.has_value());
 }
 
-INSTANTIATE_TEST_SUITE_P(CookieStoreManagerTest,
+INSTANTIATE_TEST_SUITE_P(,
                          CookieStoreManagerTest,
                          testing::Bool() /* reset_storage_during_test */);