Remove now-nonexistent SkCountdown.h from public_headers.
Seems to be breaking Chrome's GN build.
R=rmistry@google.com
TBR=rmistry
BUG=skia:
Author: senorblanco@chromium.org
Review URL: https://codereview.chromium.org/359183002
diff --git a/gyp/public_headers.gypi b/gyp/public_headers.gypi
index 7001d79..d6c7629 100644
--- a/gyp/public_headers.gypi
+++ b/gyp/public_headers.gypi
@@ -119,7 +119,6 @@
'utils/SkCamera.h',
'utils/SkLua.h',
'utils/SkParsePaint.h',
- 'utils/SkCountdown.h',
'utils/SkRunnable.h',
'utils/SkParse.h',
'utils/SkThreadPool.h',