Enable clear/purge for failed digests

golden/go/skiacorrectness/main2.go

Index: golden/go/skiacorrectness/main2.go
diff --git a/golden/go/skiacorrectness/main2.go b/golden/go/skiacorrectness/main2.go
index 8a9c5691074ce09d88908cc8488f259638480ec6..d27e83574f12615cb87e50863df5273cb3ba48e0 100644
--- a/golden/go/skiacorrectness/main2.go
+++ b/golden/go/skiacorrectness/main2.go
@@ -1410,9 +1410,32 @@ func failureListJSONHandler(w http.ResponseWriter, r *http.Request) {
 		ret.DigestFailures = append(ret.DigestFailures, failure)
 	}
 
+	sort.Sort(sort.Reverse(diff.DigestFailureSlice(ret.DigestFailures)))
 	sendJsonResponse(w, &ret)
 }
 
+// failureClearJSONHandler removes digests from the local cache.
+func failureClearJSONHandler(w http.ResponseWriter, r *http.Request) {
+	user := login.LoggedInAs(r)
+	if user == "" {
+		util.ReportError(w, r, fmt.Errorf("Not logged in."), "You must be logged in to clear digests.")
+		return
+	}
+
+	digests := []string{}
+	dec := json.NewDecoder(r.Body)
+	if err := dec.Decode(&digests); err != nil {
+		util.ReportError(w, r, err, "Unable to decode digest list.")
+		return
+	}
+	purgeGS := r.URL.Query().Get("purge") == "true"
+
+	if err := storages.DiffStore.PurgeDigests(digests, purgeGS); err != nil {
+		util.ReportError(w, r, err, "Unable to clear digests.")
+	}
+	failureListJSONHandler(w, r)
+}
+
 // listTrybotsJSONHandler returns a list of issues (Rietveld) that have
 // trybot results associated with them.
 func listTrybotsJSONHandler(w http.ResponseWriter, r *http.Request) {