Factor iOS native image loading into a utility function.

ios/chrome/browser/ui/uikit_ui_util.h

 // 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.
 
 #ifndef IOS_CHROME_BROWSER_UI_UIKIT_UI_UTIL_H_
 #define IOS_CHROME_BROWSER_UI_UIKIT_UI_UTIL_H_
 
 #include <CoreGraphics/CoreGraphics.h>
 #import <Foundation/Foundation.h>
 #import <UIKit/UIKit.h>
@@ skipping 86 matching lines @@
                          green:((CGFloat)((rgb & 0x00FF00) >> 8)) / 255.0
                           blue:((CGFloat)(rgb & 0x0000FF)) / 255.0
                          alpha:alpha];
 }
 
 // Returns whether an image contains an alpha channel. If yes, displaying the
 // image will require blending.
 // Intended for use in debug.
 BOOL ImageHasAlphaChannel(UIImage* image);
 
+// Returns the image from the shared resource bundle with the image id
+// |imageID|. If |reversable| is YES and RTL layout is in use, the image
+// will be flipped for RTL.
+UIImage* NativeReversableImage(int imageID, BOOL reversable);
+
+// Convenience version of NativeReversableImage for images that are never
+// reversable; equivalent to NativeReversableImage(imageID, NO).
+UIImage* NativeImage(int imageID);
+
 // Returns an image resized to |targetSize|. It first calculate the projection
 // by calling CalculateProjection() and then create a new image of the desired
 // size and project the correct subset of the original image onto it.
 // The resulting image will have an alpha channel.
 //
 // Image interpolation level for resizing is set to kCGInterpolationDefault.
 //
 // The resize always preserves the scale of the original image.
 UIImage* ResizeImage(UIImage* image,
                      CGSize targetSize,
@@ skipping 143 matching lines @@
 bool IsCompactTablet(id<UITraitEnvironment> environment);
 
 // Whether the main application window's rootViewController has a compact
 // iPad horizontal size class.
 bool IsCompactTablet();
 
 // Returns the current first responder.
 UIResponder* GetFirstResponder();
 
 #endif  // IOS_CHROME_BROWSER_UI_UIKIT_UI_UTIL_H_