b=359002, single-pixel images are being drawn with wrong color; bugfix to previous patch, r=stuart

gfx/thebes/public/gfxColor.h

@@ -80,14 +80,16 @@ struct THEBES_API gfxRGBA {
      */
     gfxRGBA(PRUint32 c, PackedColorType colorType = PACKED_ABGR) {
         if (colorType == PACKED_ABGR ||
-            colorType == PACKED_XBGR)
+            colorType == PACKED_XBGR ||
+            colorType == PACKED_ABGR_PREMULTIPLIED)
         {
             r = ((c >> 0) & 0xff) / 255.0;
             g = ((c >> 8) & 0xff) / 255.0;
             b = ((c >> 16) & 0xff) / 255.0;
             a = ((c >> 24) & 0xff) / 255.0;
         } else if (colorType == PACKED_ARGB ||
-                   colorType == PACKED_XRGB)
+                   colorType == PACKED_XRGB ||
+                   colorType == PACKED_ARGB_PREMULTIPLIED)
         {
             b = ((c >> 0) & 0xff) / 255.0;
             g = ((c >> 8) & 0xff) / 255.0;