[ios] Convert BlockedPopupHandler into a tab helper class.

ios/chrome/browser/web/blocked_popup_tab_helper.h

 // Copyright 2012 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_BROWSER_WEB_BLOCKED_POPUP_HANDLER_H_
-#define IOS_CHROME_BROWSER_WEB_BLOCKED_POPUP_HANDLER_H_
+#ifndef IOS_CHROME_BROWSER_WEB_BLOCKED_POPUP_TAB_HELPER_H_
+#define IOS_CHROME_BROWSER_WEB_BLOCKED_POPUP_TAB_HELPER_H_
 
 #import <UIKit/UIKit.h>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/scoped_observer.h"
 #include "components/infobars/core/infobar_manager.h"
+#import "ios/web/public/web_state/web_state_user_data.h"
 #include "ios/web/web_state/blocked_popup_info.h"
-#include "url/gurl.h"
-
-namespace ios {
-class ChromeBrowserState;
-}
-
-@protocol BlockedPopupHandlerDelegate;
 
 // Handles blocked popups. Will display an infobar informing the user and
 // allowing the user to add an exception and navigate to the site.
-class BlockedPopupHandler : public infobars::InfoBarManager::Observer {
+class BlockedPopupTabHelper
+    : public infobars::InfoBarManager::Observer,
+      public web::WebStateUserData<BlockedPopupTabHelper> {
  public:
-  explicit BlockedPopupHandler(ios::ChromeBrowserState* browser_state);
-  ~BlockedPopupHandler() override;
+  explicit BlockedPopupTabHelper(web::WebState* web_state);
+  ~BlockedPopupTabHelper() override;
 
-  void SetDelegate(id<BlockedPopupHandlerDelegate> delegate);
-
-  // Show the popup blocker infobar for the given popup.
+  // Shows the popup blocker infobar for the given popup.
   void HandlePopup(const web::BlockedPopupInfo& blocked_popup_info);
 
   // infobars::InfoBarManager::Observer implementation.
   void OnInfoBarRemoved(infobars::InfoBar* infobar, bool animate) override;
   void OnManagerShuttingDown(
       infobars::InfoBarManager* infobar_manager) override;
 
  private:
-  // Show the infobar for the current popups. Will also handle replacing an
+  friend class BlockedPopupTabHelperTest;
+
+  // Shows the infobar for the current popups. Will also handle replacing an
   // existing infobar with the updated count.
   void ShowInfoBar();
 
-  // The user browser state.
-  ios::ChromeBrowserState* browser_state_;
-  // The delegate that will display the infobar.
-  id<BlockedPopupHandlerDelegate> delegate_;
+  // Registers this object as an observer for the InfoBarManager associated with
+  // |web_state_|.  Does nothing if already registered.
+  void RegisterAsInfoBarManagerObserverIfNeeded(
+      infobars::InfoBarManager* infobar_manager);
+
+  // The WebState that this object is attached to.
+  web::WebState* web_state_;
   // The currently displayed infobar.
   infobars::InfoBar* infobar_;
   // The popups to open.
   std::vector<web::BlockedPopupInfo> popups_;
-  // For management of infobars::InfoBarManager::Observer registration.
+  // For management of infobars::InfoBarManager::Observer registration.  This
+  // object will not start observing the InfoBarManager until ShowInfoBars() is
+  // called.
   ScopedObserver<infobars::InfoBarManager, infobars::InfoBarManager::Observer>
       scoped_observer_;
 
-  DISALLOW_COPY_AND_ASSIGN(BlockedPopupHandler);
+  DISALLOW_COPY_AND_ASSIGN(BlockedPopupTabHelper);
 };
 
-// Methods implemented by the delegate of the BlockedPopupHandler.
-@protocol BlockedPopupHandlerDelegate
-
-// Returns the infobars::InfoBarManager.
-- (infobars::InfoBarManager*)infoBarManager;
-
-@end
-
-#endif  // IOS_CHROME_BROWSER_WEB_BLOCKED_POPUP_HANDLER_H_
+#endif  // IOS_CHROME_BROWSER_WEB_BLOCKED_POPUP_TAB_HELPER_H_