ios: Stop using __weak.

ios/web/navigation/crw_session_controller.mm

 // 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.
 
 #import "ios/web/navigation/crw_session_controller.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/format_macros.h"
@@ skipping 73 matching lines @@
 
   // The timestamp of the last time this tab is visited, represented in time
   // interval since 1970.
   NSTimeInterval _lastVisitedTimestamp;
 
   // If |YES|, override |currentEntry.useDesktopUserAgent| and create the
   // pending entry using the desktop user agent.
   BOOL _useDesktopUserAgentForNextPendingEntry;
 
   // The browser state associated with this CRWSessionController;
-  __weak web::BrowserState* _browserState;
+  web::BrowserState* _browserState;  // weak
 
   // Time smoother for navigation entry timestamps; see comment in
   // navigation_controller_impl.h
   web::TimeSmoother _timeSmoother;
 
   // XCallback parameters used to create (or clobber) the tab. Can be nil.
   XCallbackParameters* _xCallbackParameters;
 
   base::mac::ObjCPropertyReleaser _propertyReleaser_CRWSessionController;
 }
@@ skipping 780 matching lines @@
   item->SetURL(loaded_url);
   item->SetReferrer(referrer);
   item->SetTransitionType(transition);
   item->SetIsOverridingUserAgent(useDesktopUserAgent);
   item->set_is_renderer_initiated(rendererInitiated);
   return [
       [[CRWSessionEntry alloc] initWithNavigationItem:item.Pass()] autorelease];
 }
 
 @end