Shift cookie system callbacks to OnceCallback to impedance match mojo.

ios/net/cookies/cookie_store_ios_persistent_unittest.mm

Index: ios/net/cookies/cookie_store_ios_persistent_unittest.mm
diff --git a/ios/net/cookies/cookie_store_ios_persistent_unittest.mm b/ios/net/cookies/cookie_store_ios_persistent_unittest.mm
index 85706f608f672c4aece73605fe1aa677c8c43198..eb7ed90cc8e726b47afcac2d4c3a4179c25dc376 100644
--- a/ios/net/cookies/cookie_store_ios_persistent_unittest.mm
+++ b/ios/net/cookies/cookie_store_ios_persistent_unittest.mm
@@ -63,10 +63,11 @@ class CookieStoreIOSPersistentTest : public testing::Test {
   ~CookieStoreIOSPersistentTest() override {}
 
   // Gets the cookies. |callback| will be called on completion.
-  void GetCookies(const net::CookieStore::GetCookiesCallback& callback) {
+  void GetCookies(net::CookieStore::GetCookiesCallback callback) {
     net::CookieOptions options;
     options.set_include_httponly();
-    store_->GetCookiesWithOptionsAsync(kTestCookieURL, options, callback);
+    store_->GetCookiesWithOptionsAsync(kTestCookieURL, options,
+                                       std::move(callback));
   }
 
   // Sets a cookie.
@@ -119,7 +120,8 @@ TEST_F(CookieStoreIOSPersistentTest, SetCookieCallsHook) {
 TEST_F(CookieStoreIOSPersistentTest, NotSynchronized) {
   // Start fetching the cookie.
   GetCookieCallback callback;
-  GetCookies(base::Bind(&GetCookieCallback::Run, base::Unretained(&callback)));
+  GetCookies(
+      base::BindOnce(&GetCookieCallback::Run, base::Unretained(&callback)));
   // Backend loading completes.
   backend_->RunLoadedCallback();
   EXPECT_TRUE(callback.did_run());