[Clean Skeleton] Migrate code to clean/

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

-// Copyright 2016 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.
-
-// ======                        New Architecture                         =====
-// =         This code is only used in the new iOS Chrome architecture.       =
-// ============================================================================
-
-#import "ios/chrome/browser/ui/tab_grid/tab_grid_coordinator.h"
-
-#include <memory>
-
-#include "base/strings/sys_string_conversions.h"
-#import "ios/chrome/browser/browser_coordinator+internal.h"
-#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
-#import "ios/chrome/browser/ui/commands/settings_commands.h"
-#import "ios/chrome/browser/ui/commands/tab_commands.h"
-#import "ios/chrome/browser/ui/commands/tab_grid_commands.h"
-#import "ios/chrome/browser/ui/settings/settings_coordinator.h"
-#import "ios/chrome/browser/ui/tab/tab_coordinator.h"
-#import "ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.h"
-#import "ios/web/public/navigation_manager.h"
-#include "ios/web/public/web_state/web_state.h"
-#import "net/base/mac/url_conversions.h"
-#include "ui/base/page_transition_types.h"
-
-#if !defined(__has_feature) || !__has_feature(objc_arc)
-#error "This file requires ARC support."
-#endif
-
-@interface TabGridCoordinator ()<TabGridDataSource,
-                                 SettingsCommands,
-                                 TabCommands,
-                                 TabGridCommands>
-@property(nonatomic, strong) TabGridViewController* viewController;
-@property(nonatomic, weak) SettingsCoordinator* settingsCoordinator;
-@end
-
-@implementation TabGridCoordinator {
-  std::unique_ptr<web::WebState> _placeholderWebState;
-}
-
-@synthesize viewController = _viewController;
-@synthesize settingsCoordinator = _settingsCoordinator;
-
-#pragma mark - BrowserCoordinator
-
-- (void)start {
-  self.viewController = [[TabGridViewController alloc] init];
-  self.viewController.dataSource = self;
-  self.viewController.settingsCommandHandler = self;
-  self.viewController.tabCommandHandler = self;
-  self.viewController.tabGridCommandHandler = self;
-
-  // |rootViewController| is nullable, so this is by design a no-op if it hasn't
-  // been set. This may be true in a unit test, or if this coordinator is being
-  // used as a root coordinator.
-  [self.rootViewController presentViewController:self.viewController
-                                        animated:YES
-                                      completion:nil];
-}
-
-#pragma mark - TabGridDataSource
-
-- (NSUInteger)numberOfTabsInTabGrid {
-  return 1;
-}
-
-- (NSString*)titleAtIndex:(NSInteger)index {
-  // Placeholder implementation: ignore |index| and return the placeholder
-  // web state, lazily creating it if needed.
-  if (!_placeholderWebState.get()) {
-    web::WebState::CreateParams webStateCreateParams(self.browserState);
-    _placeholderWebState = web::WebState::Create(webStateCreateParams);
-    _placeholderWebState->SetWebUsageEnabled(true);
-  }
-  GURL url = _placeholderWebState.get()->GetVisibleURL();
-  NSString* urlText = @"<New Tab>";
-  if (!url.is_valid()) {
-    urlText = base::SysUTF8ToNSString(url.spec());
-  }
-  return urlText;
-}
-
-#pragma mark - TabCommands
-
-- (void)showTabAtIndexPath:(NSIndexPath*)indexPath {
-  DCHECK(_placeholderWebState);
-
-  TabCoordinator* tabCoordinator = [[TabCoordinator alloc] init];
-  tabCoordinator.webState = _placeholderWebState.get();
-  tabCoordinator.presentationKey = indexPath;
-  [self addChildCoordinator:tabCoordinator];
-  [tabCoordinator start];
-}
-
-#pragma mark - TabGridCommands
-
-- (void)showTabGrid {
-  // This object should only ever have at most one child.
-  DCHECK_LE(self.children.count, 1UL);
-  BrowserCoordinator* child = [self.children anyObject];
-  [child stop];
-  [self removeChildCoordinator:child];
-}
-
-#pragma mark - SettingsCommands
-
-- (void)showSettings {
-  SettingsCoordinator* settingsCoordinator = [[SettingsCoordinator alloc] init];
-  settingsCoordinator.settingsCommandHandler = self;
-  [self addOverlayCoordinator:settingsCoordinator];
-  self.settingsCoordinator = settingsCoordinator;
-  [settingsCoordinator start];
-}
-
-- (void)closeSettings {
-  [self.settingsCoordinator stop];
-  [self.settingsCoordinator.parentCoordinator
-      removeChildCoordinator:self.settingsCoordinator];
-  // self.settingsCoordinator should be presumed to be nil after this point.
-}
-
-#pragma mark - URLOpening
-
-- (void)openURL:(NSURL*)URL {
-  [self.overlayCoordinator stop];
-  [self removeOverlayCoordinator];
-  web::NavigationManager::WebLoadParams params(net::GURLWithNSURL(URL));
-  params.transition_type = ui::PAGE_TRANSITION_LINK;
-  _placeholderWebState->GetNavigationManager()->LoadURLWithParams(params);
-  if (!self.children.count) {
-    // Placeholder — since there's only one tab in the grid, just open
-    // the tab at index path (0,0).
-    [self showTabAtIndexPath:[NSIndexPath indexPathForItem:0 inSection:0]];
-  }
-}
-
-@end