Created TestRedirectObserver.

ios/web/public/test/test_redirect_observer.h

Index: ios/web/public/test/test_redirect_observer.h
diff --git a/ios/web/public/test/test_redirect_observer.h b/ios/web/public/test/test_redirect_observer.h
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+// 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_TEST_REDIRECT_OBSERVER_H_
+#define IOS_WEB_PUBLIC_TEST_TEST_REDIRECT_OBSERVER_H_
+
+#include <map>
+#include <set>
+
+#include "ios/web/public/web_state/web_state_observer.h"
+#include "url/gurl.h"
+
+namespace web {
+
+class NavigationItem;
+
+// A utility class that is used to track redirects during tests to enable URL
+// verification for redirected page loads.
+class TestRedirectObserver : public web::WebStateObserver {
+ public:
+  // Getter that lazily instantiates a TestRedirectObserver that is stored in
+  // |web_state|'s user data.
+  static TestRedirectObserver* FromWebState(WebState* web_state);
+
+  // Notifies the observer that |url| is about to be loaded by the associated
+  // WebState, triggering the TestRedirectObserver to start observing redirects.
+  void BeginObservingRedirectsForUrl(const GURL& url);
+
+  // Returns the final url in the redirect chain that began with |url|.
+  GURL GetFinalUrlForUrl(const GURL& url);
+
+ private:
+  // TestRedirectObservers must be instantiated using |FromWebState()|.
+  friend class TestRedirectObserverUserDataWrapper;
+  TestRedirectObserver();
+  TestRedirectObserver(WebState* web_state);
+  ~TestRedirectObserver() final;
+
+  // WebStateObserver:
+  void ProvisionalNavigationStarted(const GURL& url) override;
+
+  // RedirectChains store the original and final redirect URLs for a given page
+  // load.
+  typedef struct RedirectChain {
+    GURL original_url;
+    GURL final_url;
+  } RedirectChain;
+
+  // Stores redirect chains with their corresponding NavigationItems.
+  std::map<NavigationItem*, RedirectChain> redirect_chains_;
+  // Stores URLs passed into |BeginObservingRedirectsForUrl()|.  Once a
+  // provisional load has begin for a URL contained in this set, the URL will
+  // be removed and the redirect chain originating from that URL will be stored
+  // in |redirect_chains_|.
+  std::set<GURL> expected_urls_;
+};
+
+}  // namespace web
+
+#endif  // IOS_WEB_PUBLIC_TEST_TEST_REDIRECT_OBSERVER_H_