Removed CookieStoreIOS::CreateCookieStore as unused.

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 fd421874d2825017f077076387a7a29e9b16ffee..85671c9604415d193aca009dcabe576a3ac78c39 100644
--- a/ios/net/cookies/cookie_store_ios.h
+++ b/ios/net/cookies/cookie_store_ios.h
@@ -58,11 +58,6 @@ class CookieStoreIOS : public net::CookieStore,
   // so callers should not expect these values to be populated.
   explicit CookieStoreIOS(NSHTTPCookieStorage* cookie_storage);
 
-  // Creates a CookieStoreIOS with NSHTTPCookieStorage backend.
-  // TODO(crbug.com/683964): Remove this method.
-  static std::unique_ptr<CookieStoreIOS> CreateCookieStore(
-      NSHTTPCookieStorage* cookie_storage);
-
   ~CookieStoreIOS() override;
 
   enum CookiePolicy { ALLOW, BLOCK };