Make CookiePolicyBrowserTests work with SameSite changes

This change updates CookiePolicyBrowserTest to work under
SameSiteByDefaultCookies and CookiesWithoutSameSiteMustBeSecure.
This adds "SameSite=None;Secure" to some cookies which are accessed in
a third party context in tests.

Bug: 1006816
Change-Id: I7c4dc3d96f8cb718f9178fff93a000ce16c1d7f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1830288Reviewed-by: Maksim Orlovich <morlovich@chromium.org>
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Lily Chen <chlily@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708630}

content/test/data/browsing_data/site_data.html

@@ -9,8 +9,13 @@
     domAutomationController.send(false);
   }
 
+  function isHttps_() {
+    return location.protocol === 'https:';
+  }
+
   function setCookie() {
-    document.cookie = 'foo=bar; Max-Age=1000';
+    const samesite_none_secure = '; SameSite=None; Secure';
+    document.cookie = 'foo=bar; Max-Age=1000' + (isHttps_() ? samesite_none_secure : '');
     success_();
   }
 
@@ -19,7 +24,8 @@
   }
 
   function setSessionCookie() {
-    document.cookie = 'bar=session';
+    const samesite_none_secure = '; SameSite=None; Secure';
+    document.cookie = 'bar=session' + (isHttps_() ? samesite_none_secure : '');
     success_();
   }
 
@@ -155,4 +161,4 @@
   and BrowsingDataRemoverBrowserTest::SetDataForType.
 </body>
 
-</html>
\ No newline at end of file
+</html>