Factor iOS native image loading into a utility function.

ios/chrome/browser/ui/tab_switcher/tab_switcher_controller.mm

 // Copyright 2015 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/ui/tab_switcher/tab_switcher_controller.h"
 
 #include "base/ios/block_types.h"
 #include "base/ios/weak_nsobject.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/metrics/user_metrics.h"
@@ skipping 27 matching lines @@
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_panel_cell.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_panel_controller.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_panel_overlay_view.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_panel_view.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_session_cell_data.h"
 #include "ios/chrome/browser/ui/tab_switcher/tab_switcher_transition_context.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_view.h"
 #import "ios/chrome/browser/ui/toolbar/toolbar_controller.h"
 #import "ios/chrome/browser/ui/toolbar/toolbar_owner.h"
 #include "ios/chrome/browser/ui/ui_util.h"
+#import "ios/chrome/browser/ui/uikit_ui_util.h"
 #include "ios/chrome/grit/ios_strings.h"
 #include "ios/chrome/grit/ios_theme_resources.h"
 #import "ios/third_party/material_components_ios/src/components/Palettes/src/MaterialPalettes.h"
 #import "ios/web/public/navigation_manager.h"
 #include "ios/web/public/referrer.h"
 #import "ios/web/web_state/ui/crw_web_controller.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/l10n_util_mac.h"
-#include "ui/base/resource/resource_bundle.h"
 
 namespace {
 
 // Offsets for computing the panels' indexes in the TabSwitcherView.
 const int kSignInPromoPanelIndex = 2;
 const int kHeaderDistantSessionIndexOffset = 2;
 const int kLocalTabsOffTheRecordPanelIndex = 0;
 const int kLocalTabsOnTheRecordPanelIndex = 1;
 // The duration of the tab switcher toggle animation.
 const CGFloat kTransitionAnimationDuration = 0.25;
@@ skipping 598 matching lines @@
   [placeholderView addSubview:finalToolbarScreenshotImageView];
 
   UIView* toolbarScreenshotImageView =
       transitionContextContent.toolbarSnapshotView;
   toolbarScreenshotImageView.autoresizingMask = UIViewAutoresizingNone;
   toolbarScreenshotImageView.frame = initialToolbarScreenshotFrame;
   [placeholderView addSubview:toolbarScreenshotImageView];
 
   base::scoped_nsobject<UIImageView> toolbarShadowImageView(
       [[UIImageView alloc] initWithFrame:shadowInitialFrame]);
-  ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-  gfx::Image shadow = rb.GetNativeImageNamed(IDR_IOS_TOOLBAR_SHADOW);
   [toolbarShadowImageView setAutoresizingMask:UIViewAutoresizingNone];
-  [toolbarShadowImageView setImage:shadow.ToUIImage()];
+  [toolbarShadowImageView setImage:NativeImage(IDR_IOS_TOOLBAR_SHADOW)];
   [placeholderView addSubview:toolbarShadowImageView];
 
   [self.view addSubview:placeholderView];
 
   [selectedCell setHidden:YES];
   toolbarScreenshotImageView.alpha =
       (transitionType == TransitionType::TRANSITION_DISMISS) ? 0 : 1.0;
 
   base::WeakNSObject<TabSwitcherController> weakSelf(self);
   void (^completionBlock)(BOOL) = ^(BOOL) {
@@ skipping 551 matching lines @@
         base::UserMetricsAction("MobileTabSwitcherCloseNonIncognitoTab"));
   }
 }
 
 - (void)tabSwitcherPanelControllerDidUpdateOverlayViewVisibility:
     (TabSwitcherPanelController*)tabSwitcherPanelController {
   [_tabSwitcherView updateOverlayButtonState];
 }
 
 @end