Disable kSameSiteByDefaultCookies feature for CookieSettingsTest

This changed modified the test fixture, CookieSettingsTest, to both
add a feature-list and disable kSameSiteByDefaultCookies.

This prevents tests from breaking when cookies become
SameSite-by-Default.

Bug: 1016512
Change-Id: I4a31ae48467f79883b58fa275478a5e5a58e61ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1877253
Commit-Queue: Balazs Engedy <engedy@chromium.org>
Reviewed-by: Balazs Engedy <engedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709972}

components/content_settings/core/browser/cookie_settings_unittest.cc

@@ -67,6 +67,8 @@ class CookieSettingsTest : public testing::Test {
         kHttpsSubdomainSite("https://www.example.com"),
         kHttpsSite8080("https://example.com:8080"),
         kAllHttpsSitesPattern(ContentSettingsPattern::FromString("https://*")) {
+    feature_list_.InitAndDisableFeature(
+        net::features::kSameSiteByDefaultCookies);
   }
 
   ~CookieSettingsTest() override { settings_map_->ShutdownOnUIThread(); }
@@ -115,6 +117,9 @@ class CookieSettingsTest : public testing::Test {
   const GURL kHttpsSubdomainSite;
   const GURL kHttpsSite8080;
   ContentSettingsPattern kAllHttpsSitesPattern;
+
+ private:
+  base::test::ScopedFeatureList feature_list_;
 };
 
 TEST_F(CookieSettingsTest, TestWhitelistedScheme) {