Modifies GetPlatformImageColor() to check the color of a given point.

ui/gfx/image/image_unittest_util.cc

Index: ui/gfx/image/image_unittest_util.cc
diff --git a/ui/gfx/image/image_unittest_util.cc b/ui/gfx/image/image_unittest_util.cc
index 6291b23486868cc6c2a854f565e6b87dd781716f..a9110dbd1717f26fcd8506823a5320c3c7c83325 100644
--- a/ui/gfx/image/image_unittest_util.cc
+++ b/ui/gfx/image/image_unittest_util.cc
@@ -139,15 +139,19 @@ PlatformImage CopyPlatformType(const gfx::Image& image) {
 #if defined(OS_MACOSX)
 // Defined in image_unittest_util_mac.mm.
 #elif defined(TOOLKIT_GTK)
-SkColor GetPlatformImageColor(PlatformImage image) {
+SkColor GetPlatformImageColor(PlatformImage image, int x, int y) {
+  int n_channels = gdk_pixbuf_get_n_channels(image);
+  int rowstride = gdk_pixbuf_get_rowstride(image);
   guchar* gdk_pixels = gdk_pixbuf_get_pixels(image);
-  guchar alpha = gdk_pixbuf_get_has_alpha(image) ? gdk_pixels[3] : 255;
-  return SkColorSetARGB(alpha, gdk_pixels[0], gdk_pixels[1], gdk_pixels[2]);
+
+  guchar* pixel = gdk_pixels + (y * rowstride) + (x * n_channels);

[Elliot Glaysher, 2012/09/19 17:47:11]

This is probably correct everywhere. (At least you took care of the main gotcha:
rowstride can sometimes != x * n_channels; it's usually rounded up to the
nearest word.

+  guchar alpha = gdk_pixbuf_get_has_alpha(image) ? pixel[3] : 255;
+  return SkColorSetARGB(alpha, pixel[0], pixel[1], pixel[2]);
 }
 #else
-SkColor GetPlatformImageColor(PlatformImage image) {
+SkColor GetPlatformImageColor(PlatformImage image, int x, int y) {
   SkAutoLockPixels auto_lock(image);
-  return image.getColor(10, 10);
+  return image.getColor(x, y);
 }
 #endif