[IOS Tab Refactoring] Remove TabModel as a member of Tab

Update TabModelWebStateListDelegate so it doesn't need TabModel
 object as there is no need to set parentModel for the tab anymore.

Bug: 899839, 228575
Change-Id: I68ff2d4672423b36fbbb171d9f183f3506d39be5
Reviewed-on: https://chromium-review.googlesource.com/c/1320792
Commit-Queue: Mohammad Refaat <mrefaat@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611406}

ios/chrome/browser/tabs/tab.h

@@ -26,7 +26,6 @@ class GURL;
 @class FormSuggestionController;
 @protocol TabDialogDelegate;
 @class Tab;
-@class TabModel;
 
 namespace ios {
 class ChromeBrowserState;
@@ -103,11 +102,6 @@ extern NSString* const kProxyPassthroughHeaderValue;
 
 - (instancetype)init NS_UNAVAILABLE;
 
-// Sets the parent tab model for this tab.  Can only be called if the tab does
-// not already have a parent tab model set.
-// TODO(crbug.com/228575): Create a delegate interface and remove this.
-- (void)setParentTabModel:(TabModel*)model;
-
 // The view that generates print data when printing. It can be nil when printing
 // is not supported with this tab. It can be different from |Tab view|.
 - (UIView*)viewForPrinting;

ios/chrome/browser/tabs/tab.mm

@@ -58,7 +58,6 @@
 #import "ios/chrome/browser/tabs/legacy_tab_helper.h"
 #import "ios/chrome/browser/tabs/tab_dialog_delegate.h"
 #import "ios/chrome/browser/tabs/tab_helper_util.h"
-#import "ios/chrome/browser/tabs/tab_model.h"
 #import "ios/chrome/browser/tabs/tab_private.h"
 #include "ios/chrome/browser/translate/chrome_ios_translate_client.h"
 #import "ios/chrome/browser/u2f/u2f_controller.h"
@@ -121,7 +120,6 @@ NSString* const kTabClosingCurrentDocumentNotificationForCrashReporting =
 NSString* const kTabUrlKey = @"url";
 
 @interface Tab ()<CRWWebStateObserver> {
-  __weak TabModel* _parentTabModel;
   ios::ChromeBrowserState* _browserState;
 
   OpenInController* _openInController;
@@ -262,11 +260,6 @@ NSString* const kTabUrlKey = @"url";
 
 #pragma mark - Public API
 
-- (void)setParentTabModel:(TabModel*)model {
-  DCHECK(!model || !_parentTabModel);
-  _parentTabModel = model;
-}
-
 - (UIView*)viewForPrinting {
   return self.webController.viewForPrinting;
 }
@@ -446,10 +439,6 @@ NSString* const kTabUrlKey = @"url";
 
 @implementation Tab (TestingSupport)
 
-- (TabModel*)parentTabModel {
-  return _parentTabModel;
-}
-
 // TODO(crbug.com/620465): this require the Tab's WebState to be a WebStateImpl,
 // remove this helper once this is no longer true (and fix the unit tests).
 - (CRWWebController*)webController {

ios/chrome/browser/tabs/tab_model.mm

@@ -328,8 +328,7 @@ void RecordMainFrameNavigationMetric(web::WebState* web_state) {
   if ((self = [super init])) {
     _observers = [TabModelObservers observers];
 
-    _webStateListDelegate =
-        std::make_unique<TabModelWebStateListDelegate>(self);
+    _webStateListDelegate = std::make_unique<TabModelWebStateListDelegate>();
     _webStateList = std::make_unique<WebStateList>(_webStateListDelegate.get());
 
     _browserState = browserState;

ios/chrome/browser/tabs/tab_model_unittest.mm

@@ -688,20 +688,6 @@ TEST_P(TabModelTest, MoveTabs) {
   [tab_model_ removeObserver:tab_model_observer];
 }
 
-TEST_P(TabModelTest, ParentTabModel) {
-  std::unique_ptr<web::WebState> web_state = web::WebState::Create(
-      web::WebState::CreateParams(chrome_browser_state_.get()));
-  AttachTabHelpers(web_state.get(), /*for_prerender=*/false);
-
-  Tab* tab = LegacyTabHelper::GetTabForWebState(web_state.get());
-  EXPECT_NSEQ(nil, [tab parentTabModel]);
-
-  [tab_model_ webStateList]->InsertWebState(0, std::move(web_state),
-                                            WebStateList::INSERT_FORCE_INDEX,
-                                            WebStateOpener());
-  EXPECT_NSEQ(tab_model_, [tab parentTabModel]);
-}
-
 TEST_P(TabModelTest, TabCreatedOnInsertion) {
   std::unique_ptr<web::WebState> web_state = web::WebState::Create(
       web::WebState::CreateParams(chrome_browser_state_.get()));

ios/chrome/browser/tabs/tab_model_web_state_list_delegate.h

@@ -10,12 +10,11 @@
 #include "base/macros.h"
 #import "ios/chrome/browser/web_state_list/web_state_list_delegate.h"
 
-@class TabModel;
 
 // WebStateList delegate for the old architecture.
 class TabModelWebStateListDelegate : public WebStateListDelegate {
  public:
-  explicit TabModelWebStateListDelegate(TabModel* tab_model);
+  TabModelWebStateListDelegate();
   ~TabModelWebStateListDelegate() override;
 
   // WebStateListDelegate implementation.
@@ -23,8 +22,6 @@ class TabModelWebStateListDelegate : public WebStateListDelegate {
   void WebStateDetached(web::WebState* web_state) override;
 
  private:
-  __weak TabModel* tab_model_ = nil;
-
   DISALLOW_COPY_AND_ASSIGN(TabModelWebStateListDelegate);
 };
 

ios/chrome/browser/tabs/tab_model_web_state_list_delegate.mm

@@ -4,19 +4,13 @@
 
 #import "ios/chrome/browser/tabs/tab_model_web_state_list_delegate.h"
 
-#include "base/logging.h"
-#import "ios/chrome/browser/tabs/legacy_tab_helper.h"
-#import "ios/chrome/browser/tabs/tab.h"
 #import "ios/chrome/browser/tabs/tab_helper_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
-TabModelWebStateListDelegate::TabModelWebStateListDelegate(TabModel* tab_model)
-    : tab_model_(tab_model) {
-  DCHECK(tab_model_);
-}
+TabModelWebStateListDelegate::TabModelWebStateListDelegate() = default;
 
 TabModelWebStateListDelegate::~TabModelWebStateListDelegate() = default;
 
@@ -25,14 +19,7 @@ void TabModelWebStateListDelegate::WillAddWebState(web::WebState* web_state) {
   // the method is idempotent and this ensure that any WebState in a TabModel
   // has all the expected tab helpers.
   AttachTabHelpers(web_state, /*for_prerender=*/false);
-
-  DCHECK(LegacyTabHelper::FromWebState(web_state));
-  Tab* tab = LegacyTabHelper::GetTabForWebState(web_state);
-  [tab setParentTabModel:tab_model_];
 }
 
 void TabModelWebStateListDelegate::WebStateDetached(web::WebState* web_state) {
-  DCHECK(LegacyTabHelper::FromWebState(web_state));
-  Tab* tab = LegacyTabHelper::GetTabForWebState(web_state);
-  [tab setParentTabModel:nil];
 }

ios/chrome/browser/tabs/tab_private.h

@@ -18,9 +18,6 @@
 
 @interface Tab (TestingSupport)
 
-// Returns the Tab owning TabModel.
-- (TabModel*)parentTabModel;
-
 // The CRWWebController from the Tab's WebState. This should only be used
 // by tests and will be removed when Tab can wrap TestWebState (see issue
 // crbug.com/620465 for progress).