[ios] Fix done button position in tab grid

Bug: 842171
Change-Id: I225a5a3a5c23a7c0878f352f53a5e6dcec3c0df7
Reviewed-on: https://chromium-review.googlesource.com/1108741Reviewed-by: edchin <edchin@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Commit-Queue: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569177}

ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.mm

@@ -593,22 +593,11 @@ NSUInteger GetPageIndexFromPage(TabGridPage page) {
       self.topToolbar.trailingButton.hidden = NO;
       self.bottomToolbar.hidden = YES;
       self.floatingButton.hidden = NO;
-      self.doneButton = self.topToolbar.leadingButton;
-      self.closeAllButton = self.topToolbar.trailingButton;
+      self.doneButton = self.topToolbar.trailingButton;
+      self.closeAllButton = self.topToolbar.leadingButton;
       self.newTabButton = self.floatingButton;
       break;
   }
-  if (self.traitCollection.verticalSizeClass ==
-          UIUserInterfaceSizeClassRegular &&
-      self.traitCollection.horizontalSizeClass ==
-          UIUserInterfaceSizeClassRegular) {
-    // There is enough space for the tab view to have a tab strip,
-    // so put the done button on the trailing side where the tab
-    // switcher button is located on the tab view. This puts the buttons for
-    // entering and leaving the tab grid on the same corner.
-    self.doneButton = self.topToolbar.trailingButton;
-    self.closeAllButton = self.topToolbar.leadingButton;
-  }
 
   [self.doneButton setTitle:l10n_util::GetNSString(IDS_IOS_TAB_GRID_DONE_BUTTON)
                    forState:UIControlStateNormal];