[ios] Change API to inform WebStateList of opener-opened relationship.

ios/shared/chrome/browser/tabs/web_state_list.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_SHARED_CHROME_BROWSER_TABS_WEB_STATE_LIST_H_
 #define IOS_SHARED_CHROME_BROWSER_TABS_WEB_STATE_LIST_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "ui/base/page_transition_types.h"
 
 class WebStateListDelegate;
 class WebStateListObserver;
 class WebStateListOrderController;
+struct WebStateOpener;
 
 namespace web {
 class WebState;
 }
 
 // Manages a list of WebStates. May owns the WebState depending on the ownership
 // setting (initialised during construction, should eventually always be "owned"
 // once ownership of Tab is sane, see http://crbug.com/546222 for progress).
 class WebStateList {
  public:
@@ skipping 22 matching lines @@
   web::WebState* GetActiveWebState() const;
 
   // Returns the WebState at the specified index. It is invalid to call this
   // with an index such that |ContainsIndex(index)| returns false.
   web::WebState* GetWebStateAt(int index) const;
 
   // Returns the index of the specified WebState or kInvalidIndex if the
   // WebState is not in the model.
   int GetIndexOfWebState(const web::WebState* web_state) const;
 
-  // Returns the WebState that opened the WebState at the specified index or
-  // null if there is no opener on record.
-  web::WebState* GetOpenerOfWebStateAt(int index) const;
+  // Returns information about the opener of the WebState at the specified
+  // index. The structure |opener| will be null if there is no opener.
+  WebStateOpener GetOpenerOfWebStateAt(int index) const;
 
-  // Sets the opener for WebState at the specified index. The |opener| must be
-  // in the WebStateList.
-  void SetOpenerOfWebStateAt(int index, web::WebState* opener);
+  // Stores information about the opener of the WebState at the specified
+  // index. The WebStateOpener |opener| must be non-null and the WebState
+  // must be in WebStateList.
+  void SetOpenerOfWebStateAt(int index, WebStateOpener opener);
 
   // Returns the index of the next WebState in the sequence of WebStates opened
   // from the specified WebState after |start_index|, or kInvalidIndex if there
   // are no such WebState. If |use_group| is true, the opener's navigation index
   // is used to detect navigation changes within the same session.
   int GetIndexOfNextWebStateOpenedBy(const web::WebState* opener,
                                      int start_index,
                                      bool use_group) const;
 
   // Returns the index of the last WebState in the sequence of WebStates opened
   // from the specified WebState after |start_index|, or kInvalidIndex if there
   // are no such WebState. If |use_group| is true, the opener's navigation index
   // is used to detect navigation changes within the same session.
   int GetIndexOfLastWebStateOpenedBy(const web::WebState* opener,
                                      int start_index,
                                      bool use_group) const;
 
-  // Inserts the specified WebState at the specified index with an optional
-  // opener (null if there is no opener).
-  void InsertWebState(int index,
-                      web::WebState* web_state,
-                      web::WebState* opener);
+  // Inserts the specified WebState at the specified index.
+  void InsertWebState(int index, web::WebState* web_state);
 
   // Inserts the specified WebState at the best position in the WebStateList
-  // given the specified transition, opener (optional, may be null), etc. It
-  // defaults to inserting the WebState at the end of the list.
+  // given the specified transition, opener, etc. It defaults to inserting the
+  // WebState at the end of the list.
   void AppendWebState(ui::PageTransition transition,
                       web::WebState* web_state,
-                      web::WebState* opener);
+                      WebStateOpener opener);
 
   // Moves the WebState at the specified index to another index.
   void MoveWebStateAt(int from_index, int to_index);
 
   // Replaces the WebState at the specified index with new WebState. Returns
   // the old WebState at that index to the caller (abandon ownership of the
-  // returned WebState). An optional opener for the new WebState may be passed.
+  // returned WebState).
   web::WebState* ReplaceWebStateAt(int index,
-                                   web::WebState* web_state,
-                                   web::WebState* opener) WARN_UNUSED_RESULT;
+                                   web::WebState* web_state) WARN_UNUSED_RESULT;
 
   // Detaches the WebState at the specified index. Returns the detached WebState
   // to the caller (abandon ownership of the returned WebState).
   web::WebState* DetachWebStateAt(int index) WARN_UNUSED_RESULT;
 
   // Makes the WebState at the specified index the active WebState.
   void ActivateWebStateAt(int index);
 
   // Adds an observer to the model.
   void AddObserver(WebStateListObserver* observer);
@@ skipping 42 matching lines @@
   // List of observers notified of changes to the model.
   base::ObserverList<WebStateListObserver, true> observers_;
 
   // Index of the currently active WebState, kInvalidIndex if no such WebState.
   int active_index_ = kInvalidIndex;
 
   DISALLOW_COPY_AND_ASSIGN(WebStateList);
 };
 
 #endif  // IOS_SHARED_CHROME_BROWSER_TABS_WEB_STATE_LIST_H_