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

ios/web/public/test/web_test.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_PUBLIC_TEST_WEB_TEST_H_
+#define IOS_WEB_PUBLIC_TEST_WEB_TEST_H_
+
+#include "ios/web/public/test/scoped_testing_web_client.h"
+#include "ios/web/public/test/test_browser_state.h"
+#include "ios/web/public/test/test_web_thread_bundle.h"
+#include "testing/platform_test.h"
+
+namespace web {
+
+class BrowserState;
+class TestWebClient;
+
+// A test fixture for web tests that need a minimum environment set up that
+// mimics a web embedder.
+class WebTest : public PlatformTest {
+ protected:
+  WebTest();
+  ~WebTest() override;
+
+  // PlatformTest methods.
+  void SetUp() override;
+  void TearDown() override;
+
+  // Returns the WebClient that is used for testing.
+  TestWebClient* GetWebClient();
+
+  // Returns the BrowserState that is used for testing.
+  virtual BrowserState* GetBrowserState();
+
+ private:
+  // The WebClient used in tests.
+  ScopedTestingWebClient web_client_;
+  // The threads used for testing.
+  web::TestWebThreadBundle thread_bundle_;
+  // The browser state used in tests.
+  TestBrowserState browser_state_;
+};
+
+}  // namespace web
+
+#endif  // IOS_WEB_PUBLIC_TEST_WEB_TEST_H_