Revert of Enabling ico decoding with use of png and bmp decoders

dm/DM.cpp

Index: dm/DM.cpp
diff --git a/dm/DM.cpp b/dm/DM.cpp
index 44090ca1ce46ced5406554f5b5bdf8e6d3458440..833af0edbaa267c8ac9be4314a79be0443051e0a 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -146,9 +146,7 @@
 static bool codec_supported(const char* ext) {
     // FIXME: Once other versions of SkCodec are available, we can add them to this
     // list (and eventually we can remove this check once they are all supported).
-    return strcmp(ext, "png") == 0 || strcmp(ext, "PNG") == 0 || 
-           strcmp(ext, "bmp") == 0 || strcmp(ext, "BMP") == 0 ||
-           strcmp(ext, "ico") == 0 || strcmp(ext, "ICO") == 0;
+    return strcmp(ext, "png") == 0 || strcmp(ext, "PNG") == 0;
 }
 
 static void gather_srcs() {