[ios] Extracted web_test.h classes into separate files.

ios/web/test/web_test_with_web_controller.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_WEB_TEST_WEB_TEST_WITH_WEB_CONTROLLER_H_
+#define IOS_WEB_TEST_WEB_TEST_WITH_WEB_CONTROLLER_H_
+
+#import "ios/web/public/test/web_test_with_web_state.h"
+#import "ios/web/web_state/ui/crw_web_controller.h"
+
+namespace web {
+
+// Base test fixture to test CRWWebController.
+class WebTestWithWebController : public WebTestWithWebState {
+ protected:
+  WebTestWithWebController();
+  ~WebTestWithWebController() override;
+  // Returns web controller for testing.
+  CRWWebController* web_controller();
+};
+
+}  // namespace web
+
+#endif  // IOS_WEB_TEST_WEB_TEST_WITH_WEB_CONTROLLER_H_