Remove TabModelObserversBridge

The only remaining observer is didChangeTab and it wasn't part of that
bridge.

Bug: 911350
Change-Id: Ibc058d467294ce056979c730a8742ac9436d57b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1627006Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Mohammad Refaat <mrefaat@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662752}

ios/chrome/browser/tabs/BUILD.gn

@@ -49,8 +49,6 @@ source_set("tabs_internal") {
     "tab_model_list.mm",
     "tab_model_observers.h",
     "tab_model_observers.mm",
-    "tab_model_observers_bridge.h",
-    "tab_model_observers_bridge.mm",
     "tab_model_selected_tab_observer.h",
     "tab_model_selected_tab_observer.mm",
     "tab_model_synced_window_delegate.mm",

ios/chrome/browser/tabs/tab_model.mm

@@ -44,7 +44,6 @@
 #import "ios/chrome/browser/tabs/tab_model_favicon_driver_observer.h"
 #import "ios/chrome/browser/tabs/tab_model_list.h"
 #import "ios/chrome/browser/tabs/tab_model_observers.h"
-#import "ios/chrome/browser/tabs/tab_model_observers_bridge.h"
 #import "ios/chrome/browser/tabs/tab_model_selected_tab_observer.h"
 #import "ios/chrome/browser/tabs/tab_model_synced_window_delegate.h"
 #import "ios/chrome/browser/tabs/tab_model_web_state_list_delegate.h"
@@ -366,13 +365,6 @@ void RecordMainFrameNavigationMetric(web::WebState* web_state) {
         std::make_unique<WebStateListObserverBridge>(
             tabModelSelectedTabObserver));
 
-    TabModelObserversBridge* tabModelObserversBridge =
-        [[TabModelObserversBridge alloc] initWithTabModel:self
-                                        tabModelObservers:_observers];
-    [retainedWebStateListObservers addObject:tabModelObserversBridge];
-    _webStateListObservers.push_back(
-        std::make_unique<WebStateListObserverBridge>(tabModelObserversBridge));
-
     _webStateListObservers.push_back(
         std::make_unique<TabModelFaviconDriverObserver>(self, _observers));
 

ios/chrome/browser/tabs/tab_model_observers_bridge.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_CHROME_BROWSER_TABS_TAB_MODEL_OBSERVERS_BRIDGE_H_
-#define IOS_CHROME_BROWSER_TABS_TAB_MODEL_OBSERVERS_BRIDGE_H_
-
-#import "ios/chrome/browser/web_state_list/web_state_list_observer_bridge.h"
-
-@class TabModel;
-@class TabModelObservers;
-
-// Bridge WebStateListObserver events to TabModelObservers.
-@interface TabModelObserversBridge : NSObject<WebStateListObserving>
-
-- (instancetype)initWithTabModel:(TabModel*)tabModel
-               tabModelObservers:(TabModelObservers*)tabModelObservers
-    NS_DESIGNATED_INITIALIZER;
-
-- (instancetype)init NS_UNAVAILABLE;
-
-@end
-
-#endif  // IOS_CHROME_BROWSER_TABS_TAB_MODEL_OBSERVERS_BRIDGE_H_

ios/chrome/browser/tabs/tab_model_observers_bridge.mm

-// 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.
-
-#import "ios/chrome/browser/tabs/tab_model_observers_bridge.h"
-
-#include "base/logging.h"
-#import "ios/chrome/browser/tabs/legacy_tab_helper.h"
-#import "ios/chrome/browser/tabs/tab_model_observers.h"
-
-#if !defined(__has_feature) || !__has_feature(objc_arc)
-#error "This file requires ARC support."
-#endif
-
-@implementation TabModelObserversBridge {
-  // The TabModel owning self.
-  __weak TabModel* _tabModel;
-
-  // The TabModelObservers that forward events to TabModelObserver instances
-  // registered with owning TabModel.
-  __weak TabModelObservers* _tabModelObservers;
-}
-
-- (instancetype)initWithTabModel:(TabModel*)tabModel
-               tabModelObservers:(TabModelObservers*)tabModelObservers {
-  DCHECK(tabModel);
-  DCHECK(tabModelObservers);
-  if ((self = [super init])) {
-    _tabModel = tabModel;
-    _tabModelObservers = tabModelObservers;
-  }
-  return self;
-}
-
-@end