Ignore the alpha bit for 32-bit ico images.

The 32-bit images have a full alpha channel so a dedicated alpha
bit is unecessary. This CL mirrors an identical change in Skia...

http://code.google.com/p/skia/source/detail?spec=svn2187&r=2051

bug: 5003756
Change-Id: Id3eab2e12aa49c0193d87df255a78758ba080d60
1 file changed