Add unittest to test CWVWebView.

ios/web_view/test/chrome_web_view_test.h

+// Copyright 2017 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_VIEW_TEST_CHROME_WEB_VIEW_TEST_H_
+#define IOS_WEB_VIEW_TEST_CHROME_WEB_VIEW_TEST_H_
+
+#include <memory>
+#include <string>
+
+#include "testing/platform_test.h"
+
+namespace net {
+namespace test_server {
+class EmbeddedTestServer;
+}  // namespace test_server
+}  // namespace net
+
+@class CWVWebView;
+class GURL;
+@class NSURL;
+
+namespace ios_web_view {
+
+class ChromeWebViewTest : public PlatformTest {

[Eugene But (OOO till 7-30), 2017/05/24 15:32:14]

Do you want to explain in the comments what this fixture does in Setup?

[michaeldo, 2017/05/24 16:37:08]

Done.

+ protected:
+  ChromeWebViewTest();
+  ~ChromeWebViewTest() override;
+
+  // Returns URL to an html page with title set to |title|.
+  GURL GetUrlForPageWithTitle(const std::string& title);
+
+  // Returns URL to an html page with |html| within page's body tags.
+  GURL GetUrlForPageWithHTMLBody(const std::string& html);
+
+  // Loads |URL| in |web_view| and waits until the load completes. Asserts if
+  // loading does not complete.
+  void LoadUrl(CWVWebView* web_view, NSURL* url);
+
+  // Waits until |web_view| stops loading. Asserts if loading does not complete.
+  void WaitForPageLoadCompletion(CWVWebView* web_view);
+
+  // PlatformTest methods.
+  void SetUp() override;
+
+  // Embedded server for handling responses to urls as registered by
+  // net/test/embedded_test_server/default_handlers.h and the GetURLForPageWith*
+  // methods.
+  std::unique_ptr<net::test_server::EmbeddedTestServer> test_server_;
+};
+
+}  // namespace ios_web_view
+
+#endif  // IOS_WEB_VIEW_TEST_CHROME_WEB_VIEW_TEST_H_