Implement updateViaCache flag and no-cache by default for main service worker scripts

third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerUpdateViaCache.h

Index: third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerUpdateViaCache.h
diff --git a/third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerUpdateViaCache.h b/third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerUpdateViaCache.h
new file mode 100644
index 0000000000000000000000000000000000000000..5b8624e48466d49711496e7688cfcb0866277155
--- /dev/null
+++ b/third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerUpdateViaCache.h
@@ -0,0 +1,20 @@
+// Copyright 2017 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.
+
+#ifndef WebServiceWorkerUpdateViaCache_h
+#define WebServiceWorkerUpdateViaCache_h
+
+namespace blink {
+
+enum class WebServiceWorkerUpdateViaCache {
+  kUnknown,
+  kImports,
+  kAll,
+  kNone,
+  kLast = kNone,
+};
+
+}  // namespace blink
+
+#endif  // WebServiceWorkerUpdateViaCache_h