Add a SetCanonicalCookie method for CookieMonster.

ios/net/cookies/cookie_store_ios_persistent.h

Index: ios/net/cookies/cookie_store_ios_persistent.h
diff --git a/ios/net/cookies/cookie_store_ios_persistent.h b/ios/net/cookies/cookie_store_ios_persistent.h
index ce3bd4708f34c328a9d686bca4255f3e5d296741..18dba8fbfb910481fb9cf0a1ec6f5b4c09164a91 100644
--- a/ios/net/cookies/cookie_store_ios_persistent.h
+++ b/ios/net/cookies/cookie_store_ios_persistent.h
@@ -53,6 +53,10 @@ class CookieStoreIOSPersistent : public CookieStoreIOS {
                                  CookieSameSite same_site,
                                  CookiePriority priority,
                                  const SetCookiesCallback& callback) override;
+  void SetCanonicalCookieAsync(std::unique_ptr<CanonicalCookie> cookie,
+                               bool secure_source,
+                               bool modify_http_only,
+                               const SetCookiesCallback& callback) override;
   void GetCookiesWithOptionsAsync(const GURL& url,
                                   const net::CookieOptions& options,
                                   const GetCookiesCallback& callback) override;