[iOS] Remove legacy TabModel APIs.

After crrev.com/c/1796358, some downstream code still needs the old
TabModel -initWithSessionService:browserState and -browserStateDestroyed
methods. Once the CL removing that usage lands, this CL can land,
remove the old APIs.

Change-Id: I02f82f79195b524e043c9ea41f3f961197cc9fd3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1827416Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Commit-Queue: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#701095}

ios/chrome/browser/tabs/tab_model.h

@@ -82,10 +82,6 @@ NSUInteger const kTabPositionAutomatically = NSNotFound;
                           webStateList:(WebStateList*)webStateList
     NS_DESIGNATED_INITIALIZER;
 
-// Temporary backwards compatibility init which creates a webStateList.
-- (instancetype)initWithSessionService:(SessionServiceIOS*)service
-                          browserState:(ios::ChromeBrowserState*)browserState;
-
 - (instancetype)init NS_UNAVAILABLE;
 
 // Add/modify tabs.
@@ -141,9 +137,6 @@ NSUInteger const kTabPositionAutomatically = NSNotFound;
 // the tab model after this is called is unsafe.
 - (void)disconnect;
 
-// Legacy method name for -disconnect, will be deleted very soon.
-- (void)browserStateDestroyed;
-
 @end
 
 #endif  // IOS_CHROME_BROWSER_TABS_TAB_MODEL_H_

ios/chrome/browser/tabs/tab_model.mm

@@ -243,10 +243,6 @@ void RecordMainFrameNavigationMetric(web::WebState* web_state) {
 
   // Used to observe owned Tabs' WebStates.
   std::unique_ptr<web::WebStateObserver> _webStateObserver;
-
-  // Legacy ivars for backwards compatibility with some tests
-  std::unique_ptr<WebStateListDelegate> _legacyWebStateListDelegate;
-  std::unique_ptr<WebStateList> _legacyOwnedWebStateList;
 }
 
 // Session window for the contents of the tab model.
@@ -376,17 +372,6 @@ void RecordMainFrameNavigationMetric(web::WebState* web_state) {
   return self;
 }
 
-- (instancetype)initWithSessionService:(SessionServiceIOS*)service
-                          browserState:(ios::ChromeBrowserState*)browserState {
-  _legacyWebStateListDelegate = std::make_unique<BrowserWebStateListDelegate>();
-  _legacyOwnedWebStateList =
-      std::make_unique<WebStateList>(_legacyWebStateListDelegate.get());
-
-  return [self initWithSessionService:service
-                         browserState:browserState
-                         webStateList:_legacyOwnedWebStateList.get()];
-}
-
 - (web::WebState*)insertWebStateWithURL:(const GURL&)URL
                                referrer:(const web::Referrer&)referrer
                              transition:(ui::PageTransition)transition
@@ -520,10 +505,6 @@ void RecordMainFrameNavigationMetric(web::WebState* web_state) {
   _webStateObserver.reset();
 }
 
-- (void)browserStateDestroyed {
-  [self disconnect];
-}
-
 #pragma mark - SessionWindowRestoring(public)
 
 - (void)saveSessionImmediately:(BOOL)immediately {