Factor iOS native image loading into a utility function.

ios/chrome/browser/ui/tab_switcher/tab_switcher_panel_cell.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_panel_cell.h"
 
 #include "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/tabs/tab.h"
 #import "ios/chrome/browser/ui/fade_truncated_label.h"
 #import "ios/chrome/browser/ui/image_util.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_button.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_cache.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_utils.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/third_party/material_roboto_font_loader_ios/src/src/MaterialRobotoFontLoader.h"
 #import "ios/third_party/material_text_accessibility_ios/src/src/MDFTextAccessibility.h"
 #include "ui/base/l10n/l10n_util.h"
-#include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
 #include "url/gurl.h"
 
 namespace gfx {
 class ImageSkia;
 }
 
 namespace {
 const CGFloat kFontSize = 16;
 const CGFloat kCellCornerRadius = 2;
@@ skipping 97 matching lines @@
     _snapshotButton.reset([[TabSwitcherButton alloc] initWithFrame:CGRectZero]);
     [_snapshotButton setTranslatesAutoresizingMaskIntoConstraints:NO];
     [_snapshotButton addTarget:self
                         action:@selector(snapshotPressed)
               forControlEvents:UIControlEventTouchUpInside];
     [[self containerView] addSubview:_snapshotButton];
 
     // Shadow view.
     _shadow.reset([[UIImageView alloc] initWithFrame:CGRectZero]);
     [_shadow setTranslatesAutoresizingMaskIntoConstraints:NO];
-    ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-    gfx::Image shadow = rb.GetNativeImageNamed(IDR_IOS_TOOLBAR_SHADOW);
-    [_shadow setImage:shadow.ToUIImage()];
+    [_shadow setImage:NativeImage(IDR_IOS_TOOLBAR_SHADOW)];
     [[self containerView] addSubview:_shadow];
 
     // Constraints on the Top bar, snapshot view, and shadow view.
     NSDictionary* viewsDictionary = @{
       @"bar" : _topBar.get(),
       @"shadow" : _shadow.get(),
       @"snapshot" : _snapshot.get(),
       @"snapshotButton" : _snapshotButton.get(),
     };
     NSArray* constraints = @[
@@ skipping 67 matching lines @@
   DCHECK(!ImageHasAlphaChannel(image));
   [_snapshot setImage:image];
 }
 
 - (void)setAppearanceForTab:(Tab*)tab cellSize:(CGSize)cellSize {
   [_titleLabel setText:tab.title];
   [self contentView].accessibilityLabel = tab.title;
   if (tab.favicon) {
     [_favicon setImage:tab.favicon];
   } else {
-    // No favicon is available, use placeholder instead.
-    ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-    [_favicon
-        setImage:rb.GetNativeImageNamed(IDR_IOS_OMNIBOX_HTTP).ToUIImage()];
+    [_favicon setImage:NativeImage(IDR_IOS_OMNIBOX_HTTP)];
   }
 
   CGSize snapshotSize = cellSize;
   snapshotSize.height -= tabSwitcherLocalSessionCellTopBarHeight();
   base::WeakNSObject<TabSwitcherLocalSessionCell> weakCell(self);
   _currentPendingSnapshotRequest =
       [[self cache] requestSnapshotForTab:tab
                                  withSize:snapshotSize
                           completionBlock:^(UIImage* image) {
                             DCHECK([NSThread isMainThread]);
@@ skipping 204 matching lines @@
 - (void)prepareForReuse {
   [_newTabIcon setAlpha:0];
   [_faviconObtainer cancel];
   _faviconObtainer.reset();
   [_raisedButton setAlpha:0];
   [_raisedButton resetState];
   [super prepareForReuse];
 }
 
 @end