Add a SetCanonicalCookie method for CookieMonster.

ios/net/cookies/cookie_store_ios.h

Index: ios/net/cookies/cookie_store_ios.h
diff --git a/ios/net/cookies/cookie_store_ios.h b/ios/net/cookies/cookie_store_ios.h
index 85671c9604415d193aca009dcabe576a3ac78c39..68ac20f377fbd7fee82e51742c446424551ce88b 100644
--- a/ios/net/cookies/cookie_store_ios.h
+++ b/ios/net/cookies/cookie_store_ios.h
@@ -89,6 +89,10 @@ class CookieStoreIOS : public net::CookieStore,
                                  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;