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

dm/DM.cpp

 #include "CrashHandler.h"
 #include "DMJsonWriter.h"
 #include "DMSrcSink.h"
 #include "DMSrcSinkAndroid.h"
 #include "OverwriteLine.h"
 #include "ProcStats.h"
 #include "SkBBHFactory.h"
 #include "SkChecksum.h"
 #include "SkCommonFlags.h"
 #include "SkForceLinking.h"
@@ skipping 128 matching lines @@
         !SkCommandLineFlags::ShouldSkip(FLAGS_match, src->name().c_str())) {
         Tagged<Src>& s = gSrcs.push_back();
         s.reset(src.detach());
         s.tag = tag;
     }
 }
 
 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() {
     for (const skiagm::GMRegistry* r = skiagm::GMRegistry::Head(); r; r = r->next()) {
         push_src("gm", new GMSrc(r->factory()));
     }
     for (int i = 0; i < FLAGS_skps.count(); i++) {
         const char* path = FLAGS_skps[i];
         if (sk_isdir(path)) {
             SkOSFile::Iter it(path, "skp");
@@ skipping 477 matching lines @@
     }
     return 0;
 }
 
 #if !defined(SK_BUILD_FOR_IOS) && !defined(SK_BUILD_FOR_NACL)
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return dm_main();
 }
 #endif