Push API: use an enum to indicate status.

content/public/common/push_messaging_status.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/public/common/push_messaging_status.h"
+
+#include "base/logging.h"
+
+namespace content {
+
+const char* PushMessagingStatusToString(PushMessagingStatus status) {
+  switch (status) {
+    case PUSH_MESSAGING_STATUS_OK:
+      return "Operation has succeeded";
+
+    case PUSH_MESSAGING_STATUS_REGISTRATION_FAILED_NO_SERVICE_WORKER:
+      return "Registration failed - no Service Worker";
+
+    case PUSH_MESSAGING_STATUS_REGISTRATION_FAILED_SERVICE_NOT_AVAILABLE:
+      return "Registration failed - push service not available";
+
+    case PUSH_MESSAGING_STATUS_REGISTRATION_FAILED_LIMIT_REACHED:
+      return "Registration failed - registration limit has been reached";
+
+    case PUSH_MESSAGING_STATUS_REGISTRATION_FAILED_PERMISSION_DENIED:
+      return "Registration failed - permission denied";
+
+    case PUSH_MESSAGING_STATUS_REGISTRATION_FAILED_SERVICE_ERROR:
+      return "Registration failed - push service error";
+
+    case PUSH_MESSAGING_STATUS_ERROR:
+      return "Operation has failed (unspecified reason)";
+  }
+  NOTREACHED();
+  return "";
+}
+
+}  // namespace content