[ios] WebStateList owns all WebState it manages.

ios/chrome/browser/ui/preload_controller.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_UI_PRELOAD_CONTROLLER_H_
 #define IOS_CHROME_BROWSER_UI_PRELOAD_CONTROLLER_H_
 
 #import <UIKit/UIKit.h>
 
 #include <memory>
 
-#include "base/mac/scoped_nsobject.h"
 #include "components/prefs/pref_change_registrar.h"
 #import "ios/chrome/browser/net/connection_type_observer_bridge.h"
 #import "ios/chrome/browser/prefs/pref_observer_bridge.h"
 #import "ios/chrome/browser/tabs/tab_delegate.h"
 #import "ios/chrome/browser/ui/omnibox/preload_provider.h"
 #include "ios/web/public/referrer.h"
 #import "ios/web/public/web_state/ui/crw_native_content_provider.h"
 #import "net/url_request/url_fetcher.h"
 #include "ui/base/page_transition_types.h"
 #include "url/gurl.h"
 
+@protocol PreloadControllerDelegate;
+
 namespace ios {
 class ChromeBrowserState;
 }
 
-class PrefetchDelegate;
-@protocol PreloadControllerDelegate;
-@class Tab;
+namespace web {
+class WebState;
+}
 
 // ID of the URLFetcher responsible for prefetches.
 extern const int kPreloadControllerURLFetcherID;
 
 // PreloadController owns and manages a Tab that contains a prerendered
 // webpage.  This class contains methods to queue and cancel prerendering for a
 // given URL as well as a method to return the prerendered Tab.
 //
 // This class also handles queuing and canceling prefetch requests for a given
 // URL. The prefetched content is stored in the network layer cache so there is
 // no API to expose that content to users of this class.
 @interface PreloadController : NSObject<CRWNativeContentProvider,
                                         PrefObserverDelegate,
                                         PreloadProvider,
                                         TabDelegate,
-                                        CRConnectionTypeObserverBridge> {
- @private
-  ios::ChromeBrowserState* browserState_;  // Weak.
-
-  // The prerendered tab.  Can be nil.
-  base::scoped_nsobject<Tab> tab_;
-
-  // The URL that is prerendered in |tab_|.  This can be different from the
-  // value returned by |tab_.url|, for example in cases where there was a
-  // redirect.
-  //
-  // When choosing whether or not to use a prerendered Tab,
-  // BrowserViewController compares the URL being loaded by the omnibox with the
-  // URL of the prerendered Tab.  Comparing against the Tab's currently URL
-  // could return false negatives in cases of redirect, hence the need to store
-  // the originally prerendered URL.
-  GURL prerenderedURL_;
-
-  // The URL that is scheduled to be prerendered, its associated transition and
-  // referrer. |scheduledTransition_| and |scheduledReferrer_| are not valid
-  // when |scheduledURL_| is empty.
-  GURL scheduledURL_;
-  ui::PageTransition scheduledTransition_;
-  web::Referrer scheduledReferrer_;
-
-  // The most-recently prefetched URL, or nil if there have been no prefetched
-  // URLs.
-  GURL prefetchedURL_;
-
-  // The URLFetcher and associated delegate used to prefetch URLs. The delegate
-  // simply forwards callbacks from URLFetcher back to the PrerenderController.
-  std::unique_ptr<PrefetchDelegate> prefetcherDelegate_;
-  std::unique_ptr<net::URLFetcher> prefetcher_;
-
-  // Bridge to listen to pref changes.
-  std::unique_ptr<PrefObserverBridge> observerBridge_;
-  // Registrar for pref changes notifications.
-  PrefChangeRegistrar prefChangeRegistrar_;
-  // Observer for the WWAN setting.  Contains a valid object only if the
-  // instant setting is set to wifi-only.
-  std::unique_ptr<ConnectionTypeObserverBridge> connectionTypeObserverBridge_;
-
-  // Whether or not the preference is enabled.
-  BOOL enabled_;
-  // Whether or not prerendering is only when on wifi.
-  BOOL wifiOnly_;
-  // Whether or not the current connection is using WWAN.
-  BOOL usingWWAN_;
-
-  // Number of successful prerenders (i.e. the user viewed the prerendered page)
-  // during the lifetime of this controller.
-  int successfulPrerendersPerSessionCount_;
-
-  id<PreloadControllerDelegate> delegate_;  // weak
-}
-
+                                        CRConnectionTypeObserverBridge>
 // The URL of the currently prerendered Tab.  Empty if there is no prerendered
 // Tab.
 @property(nonatomic, readonly, assign) GURL prerenderedURL;
 // The URL of the currently prefetched content.  Empty if there is no prefetched
 // content.
 @property(nonatomic, readonly, assign) GURL prefetchedURL;
 @property(nonatomic, assign) id<PreloadControllerDelegate> delegate;
 
 // Designated initializer.
 - (instancetype)initWithBrowserState:(ios::ChromeBrowserState*)browserState;
 
 // Called when the browser state this object was initialized with is being
 // destroyed.
 - (void)browserStateDestroyed;
 
-// Returns the currently prerendered Tab, or nil if none exists.  The caller
-// must retain the returned Tab if needed.  After this method is called, the
-// PrerenderController reverts to a non-prerendering state.
-- (Tab*)releasePrerenderContents;
+// Returns the currently prerendered WebState, or nil if none exists.  After
+// this method is called, the PrerenderController reverts to a non-prerendering
+// state.
+- (std::unique_ptr<web::WebState>)releasePrerenderContents;
 
 // Returns true if the content of |url| has been prefetched.
 - (BOOL)hasPrefetchedURL:(const GURL&)url;
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_PRELOAD_CONTROLLER_H_