Enabling ico decoding with use of png and bmp decoders

BUG=skia:3257

Review URL: https://codereview.chromium.org/1011343003
diff --git a/dm/DM.cpp b/dm/DM.cpp
index 833af0e..44090ca 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -146,7 +146,9 @@
 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;
+    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;
 }
 
 static void gather_srcs() {