Add opener-opened relationship between WebState in WebStateList.

ios/chrome/browser/tabs/tab_model_unittest.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 <objc/runtime.h>
 
 #include "base/files/file_path.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
@@ skipping 820 matching lines @@
 
   NSString* stashPath =
       base::SysUTF8ToNSString(chrome_browser_state->GetStatePath().value());
 
   base::scoped_nsobject<TabModel> model([[TabModel alloc]
       initWithSessionWindow:session_window_.get()
              sessionService:[SessionServiceIOS sharedService]
                browserState:chrome_browser_state.get()]);
 
   [model addTabWithURL:kURL referrer:kReferrer windowName:@"window 1"];
-  [model addTabWithURL:kURL referrer:kReferrer windowName:@"window 2"];
-  [model addTabWithURL:kURL referrer:kReferrer windowName:@"window 3"];
+  [model insertTabWithURL:kURL
+                 referrer:kReferrer
+               windowName:@"window 3"
+                   opener:[model tabAtIndex:0]
+                  atIndex:[model count]];
+  [model insertTabWithURL:kURL
+                 referrer:kReferrer
+               windowName:@"window 3"
+                   opener:[model tabAtIndex:1]
+                  atIndex:0];
 
   ASSERT_EQ(3U, [model count]);
-  model.get().currentTab = [model tabAtIndex:1];
+  [model setCurrentTab:[model tabAtIndex:1]];
+
+  EXPECT_EQ(nil, [model openerOfTab:[model tabAtIndex:1]]);
+  EXPECT_EQ([model tabAtIndex:1], [model openerOfTab:[model tabAtIndex:2]]);
+  EXPECT_EQ([model tabAtIndex:2], [model openerOfTab:[model tabAtIndex:0]]);
+
   // Force state to flush to disk on the main thread so it can be immediately
   // tested below.
   SessionWindowIOS* window = [model windowForSavingSession];
   [[SessionServiceIOS sharedService] performSaveWindow:window
                                            toDirectory:stashPath];
   [model browserStateDestroyed];
   model.reset();
 
   // Restoring TabModel session sends asynchronous tasks to IO thread, wait
   // for them to complete after destroying the TabModel.
   base::RunLoop().RunUntilIdle();
 
   SessionWindowIOS* sessionWindow = [[SessionServiceIOS sharedService]
       loadWindowForBrowserState:chrome_browser_state.get()];
 
   // Create tab model from saved session.
   base::scoped_nsobject<TestSessionService> test_service(
       [[TestSessionService alloc] init]);
 
   model.reset([[TabModel alloc]
       initWithSessionWindow:sessionWindow
              sessionService:test_service
                browserState:chrome_browser_state.get()]);
-  EXPECT_EQ(model.get().currentTab, [model tabAtIndex:1]);
+  ASSERT_EQ(3u, [model count]);
+
+  EXPECT_EQ([model tabAtIndex:1], [model currentTab]);
+  EXPECT_EQ(nil, [model openerOfTab:[model tabAtIndex:1]]);
+  EXPECT_EQ([model tabAtIndex:1], [model openerOfTab:[model tabAtIndex:2]]);
+  EXPECT_EQ([model tabAtIndex:2], [model openerOfTab:[model tabAtIndex:0]]);
+
   [model browserStateDestroyed];
   model.reset();
 
   // Restoring TabModel session sends asynchronous tasks to IO thread, wait
   // for them to complete after destroying the TabModel.
   base::RunLoop().RunUntilIdle();
 
   // Clean up.
   EXPECT_TRUE([[NSFileManager defaultManager] removeItemAtPath:stashPath
                                                          error:nullptr]);
 }
 
 }  // anonymous namespace