Properly flip the CGContext during UIImage->SkBitmap conversions.

ui/gfx/image/image_unittest_util_ios.mm

Index: ui/gfx/image/image_unittest_util_ios.mm
diff --git a/ui/gfx/image/image_unittest_util_ios.mm b/ui/gfx/image/image_unittest_util_ios.mm
new file mode 100644
index 0000000000000000000000000000000000000000..f2d200d57da4eee67f70734860d000f5e2cbada9
--- /dev/null
+++ b/ui/gfx/image/image_unittest_util_ios.mm
@@ -0,0 +1,40 @@
+// 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 <CoreGraphics/CoreGraphics.h>
+#import <UIKit/UIKit.h>
+
+#include "base/mac/scoped_cftyperef.h"
+#include "skia/ext/skia_utils_ios.h"
+#include "ui/gfx/image/image_unittest_util.h"
+
+namespace gfx {
+namespace test {
+
+SkColor GetPlatformImageColor(PlatformImage image, int x, int y) {
+  // Start by extracting the target pixel into a 1x1 CGImage.
+  base::mac::ScopedCFTypeRef<CGImageRef> pixel_image(
+      CGImageCreateWithImageInRect(image.CGImage, CGRectMake(x, y, 1, 1)));
+
+  // Draw that pixel into a 1x1 bitmap context.
+  base::mac::ScopedCFTypeRef<CGColorSpaceRef> color_space(
+      CGColorSpaceCreateDeviceRGB());
+  base::mac::ScopedCFTypeRef<CGContextRef> bitmap_context(
+      CGBitmapContextCreate(/*data=*/ NULL,
+                            /*width=*/ 1, /*height=*/ 1,
+                            /*bitsPerComponent=*/ 8, /*bytesPerRow=*/ 4,
+                            color_space,
+                            kCGImageAlphaPremultipliedFirst |
+                                kCGBitmapByteOrder32Host));
+  CGContextDrawImage(bitmap_context, CGRectMake(0, 0, 1, 1), pixel_image);
+
+  // The CGBitmapContext has the same memory layout as SkColor, so we can just
+  // read an SkColor straight out of the context.
+  SkColor* data =
+      reinterpret_cast<SkColor*>(CGBitmapContextGetData(bitmap_context));

[Nico, 2012/09/24 22:48:05]

(I think the portable way to do this is bit_cast<>())

+  return *data;
+}
+
+}  // namespace test
+}  // namespace gfx