Remove unused method from TabModel

The -openerOfTab: method of the TabModel wasn't used. This CL removes
it.

Bug: none
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I79d219e52798a47da582d373b0b8e277e263a11e
Reviewed-on: https://chromium-review.googlesource.com/1122631Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572147}

ios/chrome/browser/tabs/tab_model.h

@@ -105,9 +105,6 @@ NSUInteger const kTabPositionAutomatically = NSNotFound;
 - (Tab*)tabAtIndex:(NSUInteger)index;
 - (NSUInteger)indexOfTab:(Tab*)tab;
 
-// Returns the tab which opened this tab, or nil if it's not a child.
-- (Tab*)openerOfTab:(Tab*)tab;
-
 // Add/modify tabs.
 
 // Opens a tab at the specified URL. For certain transition types, will consult

ios/chrome/browser/tabs/tab_model.mm

@@ -470,16 +470,6 @@ void RecordMainFrameNavigationMetric(web::WebState* web_state) {
   return static_cast<NSUInteger>(index);
 }
 
-- (Tab*)openerOfTab:(Tab*)tab {
-  int index = _webStateList->GetIndexOfWebState(tab.webState);
-  if (index == WebStateList::kInvalidIndex)
-    return nil;
-
-  WebStateOpener opener = _webStateList->GetOpenerOfWebStateAt(index);
-  return opener.opener ? LegacyTabHelper::GetTabForWebState(opener.opener)
-                       : nil;
-}
-
 - (Tab*)insertTabWithURL:(const GURL&)URL
                 referrer:(const web::Referrer&)referrer
               transition:(ui::PageTransition)transition

ios/chrome/browser/tabs/tab_model_unittest.mm

@@ -470,76 +470,6 @@ TEST_F(TabModelTest, InsertWithSessionController) {
   EXPECT_TRUE(current_tab);
 }
 
-TEST_F(TabModelTest, OpenerOfTab) {
-  // Start off with a couple tabs.
-  [tab_model_ insertTabWithURL:GURL(kURL1)
-                      referrer:web::Referrer()
-                    transition:ui::PAGE_TRANSITION_TYPED
-                        opener:nil
-                   openedByDOM:NO
-                       atIndex:[tab_model_ count]
-                  inBackground:NO];
-  [tab_model_ insertTabWithURL:GURL(kURL1)
-                      referrer:web::Referrer()
-                    transition:ui::PAGE_TRANSITION_TYPED
-                        opener:nil
-                   openedByDOM:NO
-                       atIndex:[tab_model_ count]
-                  inBackground:NO];
-  [tab_model_ insertTabWithURL:GURL(kURL1)
-                      referrer:web::Referrer()
-                    transition:ui::PAGE_TRANSITION_TYPED
-                        opener:nil
-                   openedByDOM:NO
-                       atIndex:[tab_model_ count]
-                  inBackground:NO];
-
-  // Create parent tab.
-  Tab* parent_tab = [tab_model_ insertTabWithURL:GURL(kURL1)
-                                        referrer:web::Referrer()
-                                      transition:ui::PAGE_TRANSITION_TYPED
-                                          opener:nil
-                                     openedByDOM:NO
-                                         atIndex:[tab_model_ count]
-                                    inBackground:NO];
-
-  // Create child tab.
-  Tab* child_tab = [tab_model_ insertTabWithURL:GURL(kURL1)
-                                       referrer:web::Referrer()
-                                     transition:ui::PAGE_TRANSITION_TYPED
-                                         opener:parent_tab
-                                    openedByDOM:NO
-                                        atIndex:[tab_model_ count]
-                                   inBackground:NO];
-
-  // Create another unrelated tab.
-  Tab* another_tab = [tab_model_ insertTabWithURL:GURL(kURL1)
-                                         referrer:web::Referrer()
-                                       transition:ui::PAGE_TRANSITION_TYPED
-                                           opener:nil
-                                      openedByDOM:NO
-                                          atIndex:[tab_model_ count]
-                                     inBackground:NO];
-
-  // Create another child of the first tab.
-  Tab* child_tab2 = [tab_model_ insertTabWithURL:GURL(kURL1)
-                                        referrer:web::Referrer()
-                                      transition:ui::PAGE_TRANSITION_TYPED
-                                          opener:parent_tab
-                                     openedByDOM:NO
-                                         atIndex:[tab_model_ count]
-                                    inBackground:NO];
-
-  EXPECT_FALSE([tab_model_ openerOfTab:parent_tab]);
-  EXPECT_FALSE([tab_model_ openerOfTab:another_tab]);
-  EXPECT_EQ(parent_tab, [tab_model_ openerOfTab:child_tab]);
-  EXPECT_EQ(parent_tab, [tab_model_ openerOfTab:child_tab2]);
-}
-
-TEST_F(TabModelTest, OpenerOfTabEmptyModel) {
-  EXPECT_FALSE([tab_model_ openerOfTab:nil]);
-}
-
 TEST_F(TabModelTest, AddWithOrderController) {
   // Create a few tabs with the controller at the front.
   Tab* parent = [tab_model_ insertTabWithURL:GURL(kURL1)
@@ -935,12 +865,6 @@ TEST_F(TabModelTest, PersistSelectionChange) {
   ASSERT_EQ(3U, [tab_model_ count]);
   [tab_model_ setCurrentTab:[tab_model_ tabAtIndex:1]];
 
-  EXPECT_EQ(nil, [tab_model_ openerOfTab:[tab_model_ tabAtIndex:1]]);
-  EXPECT_EQ([tab_model_ tabAtIndex:1],
-            [tab_model_ openerOfTab:[tab_model_ tabAtIndex:2]]);
-  EXPECT_EQ([tab_model_ tabAtIndex:2],
-            [tab_model_ openerOfTab:[tab_model_ tabAtIndex:0]]);
-
   // Force state to flush to disk on the main thread so it can be immediately
   // tested below.
   [test_session_service setPerformIO:YES];
@@ -960,11 +884,6 @@ TEST_F(TabModelTest, PersistSelectionChange) {
   ASSERT_EQ(3u, [tab_model_ count]);
 
   EXPECT_EQ([tab_model_ tabAtIndex:1], [tab_model_ currentTab]);
-  EXPECT_EQ(nil, [tab_model_ openerOfTab:[tab_model_ tabAtIndex:1]]);
-  EXPECT_EQ([tab_model_ tabAtIndex:1],
-            [tab_model_ openerOfTab:[tab_model_ tabAtIndex:2]]);
-  EXPECT_EQ([tab_model_ tabAtIndex:2],
-            [tab_model_ openerOfTab:[tab_model_ tabAtIndex:0]]);
 
   // Clean up.
   EXPECT_TRUE([[NSFileManager defaultManager] removeItemAtPath:stashPath