Change SKPs to new asset management format

BUG=skia:5427
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2169653003
DOCS_PREVIEW= https://skia.org/?cl=2169653003

Review-Url: https://codereview.chromium.org/2169653003
diff --git a/bin/fetch-skps b/bin/fetch-skps
index bac8e20..19f46e3 100755
--- a/bin/fetch-skps
+++ b/bin/fetch-skps
@@ -5,23 +5,5 @@
 set -x
 set -e
 
-VERSION=`cat $(dirname $0)/../SKP_VERSION`
-if ! gsutil -m cp -r gs://chromium-skia-gm/playback_$VERSION/skps . ; then
-    cat >&2 <<EOF
-
-    Instructions for authenticating.
-
-    Install the utilities you need:
-      curl https://sdk.cloud.google.com | bash
-
-    Authenticate
-      gcloud auth login
-
-    Follow instructions on web page.
-
-    Set Project
-      gcloud config set project google.com:skia-buildbots
-
-EOF
-exit 1
-fi
+DOWNLOAD_SCRIPT=$(cd $(dirname $0)/..; pwd)/infra/bots/assets/skp/download.py
+python ${DOWNLOAD_SCRIPT} -t $(pwd)/skps