Factor iOS native image loading into a utility function.

ios/chrome/browser/ui/overscroll_actions/overscroll_actions_view.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/overscroll_actions/overscroll_actions_view.h"
 
 #import <QuartzCore/QuartzCore.h>
 
 #include "base/logging.h"
 #include "base/mac/objc_property_releaser.h"
 #include "base/mac/scoped_nsobject.h"
 #include "ios/chrome/browser/ui/rtl_geometry.h"
+#include "ios/chrome/browser/ui/uikit_ui_util.h"
 #include "ios/chrome/grit/ios_theme_resources.h"
-#include "ui/base/resource/resource_bundle.h"
 
 namespace {
 // Actions images.
 NSString* const kNewTabActionImage = @"ptr_new_tab";
 NSString* const kNewTabActionActiveImage = @"ptr_new_tab_active";
 NSString* const kRefreshActionImage = @"ptr_reload";
 NSString* const kRefreshActionActiveImage = @"ptr_reload_active";
 NSString* const kCloseActionImage = @"ptr_close";
 NSString* const kCloseActionActiveImage = @"ptr_close_active";
 
@@ skipping 253 matching lines @@
     _refreshActionImageViewHighlighted = [[UIImageView alloc] init];
     if (UseRTLLayout()) {
       [_refreshActionImageViewHighlighted
           setTransform:CGAffineTransformMakeScale(-1, 1)];
     }
     _closeTabActionImageViewHighlighted = [[UIImageView alloc] init];
     [_highlightMaskLayer addSublayer:_addTabActionImageViewHighlighted.layer];
     [_highlightMaskLayer addSublayer:_refreshActionImageViewHighlighted.layer];
     [_highlightMaskLayer addSublayer:_closeTabActionImageViewHighlighted.layer];
 
-    _shadowView = [[UIImageView alloc] initWithFrame:CGRectZero];
-    ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-    gfx::Image shadow = rb.GetNativeImageNamed(IDR_IOS_TOOLBAR_SHADOW);
-    [_shadowView setImage:shadow.ToUIImage()];
+    _shadowView =
+        [[UIImageView alloc] initWithImage:NativeImage(IDR_IOS_TOOLBAR_SHADOW)];
     [self addSubview:_shadowView];
 
     _backgroundView = [[UIView alloc] initWithFrame:CGRectZero];
     [self addSubview:_backgroundView];
 
     if (UseRTLLayout())
       [self setTransform:CGAffineTransformMakeScale(-1, 1)];
 
     _tapGesture.reset([[UITapGestureRecognizer alloc]
         initWithTarget:self
@@ skipping 690 matching lines @@
   CGPoint tapLocation = [tapRecognizer locationInView:self];
   ios_internal::OverscrollAction action = [self actionAtLocation:tapLocation];
   if (action != ios_internal::OverscrollAction::NONE) {
     [self updateSelectionForTouchedAction:action];
     [self setSelectedAction:action];
     [self.delegate overscrollActionsViewDidTapTriggerAction:self];
   }
 }
 
 @end