Implement the "first-party-only" cookie flag.

chrome/browser/extensions/api/cookies/cookies_api.cc

Index: chrome/browser/extensions/api/cookies/cookies_api.cc
diff --git a/chrome/browser/extensions/api/cookies/cookies_api.cc b/chrome/browser/extensions/api/cookies/cookies_api.cc
index d059071dbfa1f9247c7ec32d11c135aafd0ec6bf..1f5f8f28562e1576ffb7ffc4c118bb80077fb966 100644
--- a/chrome/browser/extensions/api/cookies/cookies_api.cc
+++ b/chrome/browser/extensions/api/cookies/cookies_api.cc
@@ -385,9 +385,8 @@ void CookiesSetFunction::SetCookieOnIOThread() {
   }
 
   cookie_monster->SetCookieWithDetailsAsync(
-      url_,
-      parsed_args_->details.name.get() ? *parsed_args_->details.name
-                                       : std::string(),
+      url_, parsed_args_->details.name.get() ? *parsed_args_->details.name
+                                             : std::string(),
       parsed_args_->details.value.get() ? *parsed_args_->details.value
                                         : std::string(),
       parsed_args_->details.domain.get() ? *parsed_args_->details.domain
@@ -399,6 +398,7 @@ void CookiesSetFunction::SetCookieOnIOThread() {
                                          : false,
       parsed_args_->details.http_only.get() ? *parsed_args_->details.http_only
                                             : false,
+      false,  // TODO(mkwst): FirstParty
       net::COOKIE_PRIORITY_DEFAULT,
       base::Bind(&CookiesSetFunction::PullCookie, this));
 }