Loading/Creating images for mutiple scale factors on the fly

ui/gfx/image/image_skia_source.h

+// Copyright (c) 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 UI_GFX_IMAGE_IMAGE_SKIA_SOURCE_H_
+#define UI_GFX_IMAGE_IMAGE_SKIA_SOURCE_H_
+#pragma once
+
+#include "ui/base/layout.h"
+
+namespace gfx {
+
+class ImageSkiaRep;
+
+class ImageSkiaSource {
+ public:
+  virtual ~ImageSkiaSource() {}
+
+  // Returns the ImageSkiaRep for the given |scale_factor|.
+  virtual gfx::ImageSkiaRep GetImageForScale(ui::ScaleFactor scale_factor) = 0;

[pkotwicz, 2012/07/02 21:39:36]

Nit: rename this method to GetImageRepForScale/GetRepresentation as it returns
an ImageSkiaRep* not an ImageSkia*

[oshima, 2012/07/02 22:24:58]

ImageRep isn't correct either unless we use ImageSkiaRep. I once used
GetImageSkaiRepForScale, but it looked excessive. I also thought
that it's not helpful because this is not something you call.
It's something you have to implement and it's pretty clear that you need to
create ImageSkiaRep.
 I'd just follow OWNERS's judgement call. Ben, let me know what you think and
I'll make change.

+};
+
+}  // namespace gfx
+
+#endif  // UI_GFX_IMAGE_IMAGE_SKIA_SOURCE_H_