Add opener-opened relationship between WebState in WebStateList.

ios/chrome/browser/tabs/tab_model.mm

Index: ios/chrome/browser/tabs/tab_model.mm
diff --git a/ios/chrome/browser/tabs/tab_model.mm b/ios/chrome/browser/tabs/tab_model.mm
index f6d21cd57f9bf2b3a05480a80a23ed05b96dfe48..0a768fe2456f01e21323d0f9070d0dc0c3ffecbd 100644
--- a/ios/chrome/browser/tabs/tab_model.mm
+++ b/ios/chrome/browser/tabs/tab_model.mm
@@ -117,6 +117,27 @@ void CleanCertificatePolicyCache(
                  base::Unretained(web_state_list)));
 }
 
+// Internal helper function returning the opener for a given WebState by
+// checking the associated Tab tabId (should be removed once the opener
+// is passed to the insertTab:atIndex: and replaceTab:withTab: methods).
+web::WebState* GetOpenerForWebState(const WebStateList& web_state_list,
+                                    web::WebState* web_state) {
+  Tab* tab = LegacyTabHelper::GetTabForWebState(web_state);
+  NSString* opener_id =
+      [tab navigationManager]->GetSessionController().openerId;
+  if (!opener_id)
+    return nullptr;
+
+  for (int index = 0; index < web_state_list.count(); ++index) {
+    web::WebState* web_state = web_state_list.GetWebStateAt(index);
+    Tab* tab = LegacyTabHelper::GetTabForWebState(web_state);
+    if ([opener_id isEqualToString:tab.tabId])
+      return web_state;
+  }
+
+  return nullptr;
+}
+
 }  // anonymous namespace
 
 @interface TabModelWebStateProxyFactory : NSObject<WebStateProxyFactory>
@@ -405,68 +426,43 @@ void CleanCertificatePolicyCache(
 }
 
 - (Tab*)nextTabWithOpener:(Tab*)tab afterTab:(Tab*)afterTab {
-  NSUInteger startIndex = NSNotFound;
-  // Start looking after |afterTab|. If it's not found, start looking after
-  // |tab|. If it's not found either, bail.
+  int startIndex = WebStateList::kInvalidIndex;
   if (afterTab)
-    startIndex = [self indexOfTab:afterTab];
-  if (startIndex == NSNotFound)
-    startIndex = [self indexOfTab:tab];
-  if (startIndex == NSNotFound)
+    startIndex = _webStateList.GetIndexOfWebState(afterTab.webState);
+
+  if (startIndex == WebStateList::kInvalidIndex)
+    startIndex = _webStateList.GetIndexOfWebState(tab.webState);
+
+  const int index = _webStateList.GetIndexOfNextWebStateOpenedBy(
+      tab.webState, startIndex, false);
+  if (index == WebStateList::kInvalidIndex)
     return nil;
-  NSString* parentID = tab.tabId;
-  for (NSUInteger i = startIndex + 1; i < self.count; ++i) {
-    Tab* current = [self tabAtIndex:i];
-    DCHECK([current navigationManager]);
-    CRWSessionController* sessionController =
-        [current navigationManager]->GetSessionController();
-    if ([sessionController.openerId isEqualToString:parentID])
-      return current;
-  }
-  return nil;
+
+  DCHECK_GE(index, 0);
+  return [self tabAtIndex:static_cast<NSUInteger>(index)];
 }
 
 - (Tab*)lastTabWithOpener:(Tab*)tab {
-  NSUInteger startIndex = [self indexOfTab:tab];
-  if (startIndex == NSNotFound)
+  int startIndex = _webStateList.GetIndexOfWebState(tab.webState);
+  if (startIndex == WebStateList::kInvalidIndex)
     return nil;
-  // There is at least one tab in the model, because otherwise the above check
-  // would have returned.
-  NSString* parentID = tab.tabId;
-  DCHECK([tab navigationManager]);
-  NSInteger parentNavIndex = [tab navigationManager]->GetCurrentItemIndex();
-
-  Tab* match = nil;
-  // Find the last tab in the first matching 'group'.  A 'group' is a set of
-  // tabs whose opener's id and opener's navigation index match. The navigation
-  // index is used in addition to the session id to detect navigations changes
-  // within the same session.
-  for (NSUInteger i = startIndex + 1; i < self.count; ++i) {
-    Tab* tabToCheck = [self tabAtIndex:i];
-    DCHECK([tabToCheck navigationManager]);
-    CRWSessionController* sessionController =
-        [tabToCheck navigationManager]->GetSessionController();
-    if ([sessionController.openerId isEqualToString:parentID] &&
-        sessionController.openerNavigationIndex == parentNavIndex) {
-      match = tabToCheck;
-    } else if (match) {
-      break;
-    }
-  }
-  return match;
+
+  const int index = _webStateList.GetIndexOfLastWebStateOpenedBy(
+      tab.webState, startIndex, true);
+  if (index == WebStateList::kInvalidIndex)
+    return nil;
+
+  DCHECK_GE(index, 0);
+  return [self tabAtIndex:static_cast<NSUInteger>(index)];
 }
 
 - (Tab*)openerOfTab:(Tab*)tab {
-  if (![tab navigationManager])
-    return nil;
-  NSString* openerId = [tab navigationManager]->GetSessionController().openerId;
-  if (!openerId.length)  // Short-circuit if opener is empty.
+  int index = _webStateList.GetIndexOfWebState(tab.webState);
+  if (index == WebStateList::kInvalidIndex)
     return nil;
-  for (Tab* iteratedTab in self) {
-    if ([iteratedTab.tabId isEqualToString:openerId])
-      return iteratedTab;
-  }
-  return nil;
+
+  web::WebState* opener = _webStateList.GetOpenerOfWebStateAt(index);
+  return opener ? LegacyTabHelper::GetTabForWebState(opener) : nil;
 }
 
 - (Tab*)insertOrUpdateTabWithURL:(const GURL&)URL
@@ -559,7 +555,9 @@ void CleanCertificatePolicyCache(
   DCHECK_LE(index, static_cast<NSUInteger>(INT_MAX));
 
   [_tabRetainer addObject:tab];
-  _webStateList.InsertWebState(static_cast<int>(index), tab.webState);
+  _webStateList.InsertWebState(
+      static_cast<int>(index), tab.webState,
+      GetOpenerForWebState(_webStateList, tab.webState));
 
   // Persist the session due to a new tab being inserted. If this is a
   // background tab (will not become active), saving now will capture the
@@ -590,7 +588,9 @@ void CleanCertificatePolicyCache(
   [_tabRetainer addObject:newTab];
   [newTab setParentTabModel:self];
 
-  _webStateList.ReplaceWebStateAt(index, newTab.webState);
+  _webStateList.ReplaceWebStateAt(
+      index, newTab.webState,
+      GetOpenerForWebState(_webStateList, newTab.webState));
 
   if (self.currentTab == oldTab)
     [self changeSelectedTabFrom:nil to:newTab persistState:NO];