Factor iOS native image loading into a utility function.

ios/chrome/browser/ui/uikit_ui_util.mm

 // Copyright 2012 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/uikit_ui_util.h"
 
 #import <Accelerate/Accelerate.h>
 #import <Foundation/Foundation.h>
 #import <QuartzCore/QuartzCore.h>
 #include <stddef.h>
 #include <stdint.h>
 #import <UIKit/UIKit.h>
 #include <cmath>
 
 #include "base/ios/ios_util.h"
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
 #include "ios/chrome/browser/experimental_flags.h"
+#include "ios/chrome/browser/ui/rtl_geometry.h"
 #include "ios/chrome/browser/ui/ui_util.h"
 #include "ios/web/public/web_thread.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/l10n_util_mac.h"
+#include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/ios/uikit_util.h"
 #include "ui/gfx/scoped_cg_context_save_gstate_mac.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 
 // Linearly interpolate between |a| and |b| by fraction |f|. Satisfies
@@ skipping 185 matching lines @@
       return NO;
     case kCGImageAlphaPremultipliedLast:
     case kCGImageAlphaPremultipliedFirst:
     case kCGImageAlphaLast:
     case kCGImageAlphaFirst:
     case kCGImageAlphaOnly:
       return YES;
   }
 }
 
+UIImage* NativeReversableImage(int imageID, BOOL reversable) {
+  DCHECK(imageID);
+  ResourceBundle& rb = ResourceBundle::GetSharedInstance();
+  UIImage* image = rb.GetNativeImageNamed(imageID).ToUIImage();
+  return (reversable && UseRTLLayout())
+             ? [image imageFlippedForRightToLeftLayoutDirection]
+             : image;
+}
+
+UIImage* NativeImage(int imageID) {
+  return NativeReversableImage(imageID, NO);

[noyau (Ping after 24h), 2017/01/02 10:11:32]

Late driveby: Will this now reverse all images if UseRTLLayout() is true,
whereas before only the ones explicitely reversable were reversed?

[marq (ping after 24h), 2017/01/09 09:46:14]

NativeImage(image_id) will never reverse the image.

NativeReversableImage(image_id, YES) will reverse the image if RTLLayout() is
true; this (passing in YES) is how images are marked as explicitly reversible.

(I should fix the spelling of 'Reversable', however).

+}
+
 UIImage* ResizeImage(UIImage* image,
                      CGSize targetSize,
                      ProjectionMode projectionMode) {
   return ResizeImage(image, targetSize, projectionMode, NO);
 }
 
 UIImage* ResizeImage(UIImage* image,
                      CGSize targetSize,
                      ProjectionMode projectionMode,
                      BOOL opaque) {
@@ skipping 401 matching lines @@
   DCHECK(!gFirstResponder);
   [[UIApplication sharedApplication]
       sendAction:@selector(cr_markSelfCurrentFirstResponder)
               to:nil
             from:nil
         forEvent:nil];
   UIResponder* firstResponder = gFirstResponder;
   gFirstResponder = nil;
   return firstResponder;
 }