MacViews: Use Cocoa folder icons in tree views.

ui/gfx/image/image_skia_operations.cc

Index: ui/gfx/image/image_skia_operations.cc
diff --git a/ui/gfx/image/image_skia_operations.cc b/ui/gfx/image/image_skia_operations.cc
index f523abf54ecec41f722fe4d94d95089be90570ee..89c4a6fe69cfd4972f53d77946b543264cbf8d1d 100644
--- a/ui/gfx/image/image_skia_operations.cc
+++ b/ui/gfx/image/image_skia_operations.cc
@@ -423,6 +423,25 @@ class RotatedSource : public ImageSkiaSource {
   DISALLOW_COPY_AND_ASSIGN(RotatedSource);
 };
 
+// MirroredSource generates image reps that are mirrors of those in |source|.
+class MirroredSource : public ImageSkiaSource {

[tapted, 2016/01/14 23:43:50]

For RTL, another approach is to flip the canvas when drawing rather than
flipping the image asset. See e.g.  ImageButton::OnPaint(gfx::Canvas* canvas) {}

[karandeepb, 2016/01/18 00:31:18]

Done.

+ public:
+  MirroredSource(const ImageSkia& source) : source_(source) {}
+  ~MirroredSource() override {}
+
+  // gfx::ImageSkiaSource overrides:
+  ImageSkiaRep GetImageForScale(float scale) override {
+    const ImageSkiaRep& image_rep = source_.GetRepresentation(scale);
+    const SkBitmap mirrored_bitmap =
+        SkBitmapOperations::CreateMirroredBitmap(image_rep.sk_bitmap());
+    return ImageSkiaRep(mirrored_bitmap, image_rep.scale());
+  }
+
+ private:
+  const ImageSkia source_;
+
+  DISALLOW_COPY_AND_ASSIGN(MirroredSource);
+};
 
 }  // namespace
 
@@ -548,4 +567,12 @@ ImageSkia ImageSkiaOperations::CreateRotatedImage(
 
 }
 
+// static
+ImageSkia ImageSkiaOperations::CreateMirroredImage(const ImageSkia& source) {
+  if (source.isNull())
+    return ImageSkia();
+
+  return ImageSkia(new MirroredSource(source), source.size());
+}
+
 }  // namespace gfx