[ios] Adds test hooks to enable/disable functionality while testing.

ios/chrome/app/tests_hook.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_APP_TESTS_HOOK_H_
+#define IOS_CHROME_APP_TESTS_HOOK_H_
+
+namespace tests_hook {
+
+// Returns true if contextual search should be disabled to allow other tests
+// to run unimpeded.
+bool DisableContextualSearch();
+
+// Returns true if the first_run path should be disabled to allow other tests to
+// run unimpeded.
+bool DisableFirstRun();
+
+// Returns true if the signin recall promo should be disabled to allow other
+// tests to run unimpeded.
+bool DisableSigninRecallPromo();
+
+// Returns true if the update service should be disabled so that the update
+// infobar won't be shown during testing.
+bool DisableUpdateService();
+
+// Global integration tests setup.  This is not used by EarlGrey-based
+// integration tests.
+void SetUpTestsIfPresent();
+
+// Runs the integration tests.  This is not used by EarlGrey-based integration
+// tests.
+void RunTestsIfPresent();
+
+}  // namespace tests_hook
+
+#endif  // IOS_CHROME_APP_TESTS_HOOK_H_